Reproduction abnormality includes the loss of pregnant fetus,infertility and sterility,the birth of defected infants,and so on.Chromosomal abnormality is the one of the important reasons,at thesame time we noticed the effect of chromosomal polymorphism onreproduction abnormality. Chromosomal polymorphism is defined asall kinds of micro variation of chromotosome which reside in thenomal group generally. It shows the difference of the structure andstriation magnitde of homologous chromosome,and mainly includesthe lengthening or absence of the SC region of chromosome 1 9 16,the pericentric inversion of chromosome 9,the longitudinal variationof the short arm of chromosome D/G group and the long arm ofchromosome Y. It refers to the constitutive heterochromatin which isnot athletic in inheritance,contains reduplicative DNA sequence,andhas no transcriptive activity,so chromosomal polymorphism will notresult in severe influence upon corpuscular phaenotype commonly.But with the improvement of the chromosome banding technique,more and more data indicated that chromosomal polymorphism wasassociated with reproduction abnormality , cancer and mentalretardation.Aim:This article took on the detection rate of chromosomalpolymorphism among reproduction abnormality pations as theprimary cause to study the relationship between chromosomalpolymorphism and reproduction abnormality.Data and method:There were 229 couples with reproductionabnormality was screened in the patients who visited the first hospitaland fundamental medical college of Jilin university to docytogenetical examination during Jan,2004～Jan,2006. The clinicalfeature of screen was negative reproductive histories(includingabortion,abnormal embryo,dead embryo,still birth,neonatal death,and to give birth of deformans infants,dysgnosia infants,abnormalchromosome infants,premature infant and so on),and infertility andsterility (pregnancy does not result after 2 years of cohabitationwithout contraceptive). The peripheral blood lymphocyte cultivating,chromatosome specimen preparing by routine method and karyotypeanalysis after G banding were applied to the screened couples. theresults were analyzed after statistical treatment. 1.the detection rate ofchromosomal polymorphism and the constituent ratio of sex;2.thedetection rates and the constituent ratios of every kind ofchromosomal polymorphism;3.the detection rates and the constituentratios of chromosomal polymorphism in every kind of reproductionabnormality couples;4.the relationship between the stage of pregnantfetus loss and the detection rate of chromosomal polymorphism;5.therelationship between the times of negative reproduction and thedetection rate of chromosomal polymorphism.Result:1.There were 10.7%(49/458)cases with chromosomalpolymorphism in the 229 couples(458 cases)with reproductionabnormality,and 2.6% people with chromosomal polymorphism incommom people,there was significant difference between two groups(P0.05). 5. There were 10.9%(33/302)cases with chromosomalpolymorphism in the couples with negative reproductive histories. 8.1%(10/124) cases with chromosomal polymorphism were defected,whose negative reproduction occoured for one time;8.3%(10/120)cases were defected,whose negative reproduction occoured for twotimes;21.1 %( 8/38 ) cases were defected , whose negativereproduction occoured for three times;25%(5/20)cases weredefected,whose negative reproduction occoured for more than threetimes. With the time of negative reproduction increasing,the detectionrates of chromosomal polymorphism increased. The groups whosenegative reproduction occoured for three times and more than threetimes and the groups whose negative reproduction occoured for onetime and two times were compared respectively,there were significantdifference between their detection rates of chromosomalpolymorphism (P0.05).Discussion:1. The detection rate of chromosomal polymorphismof the couples with reproduction abnormality was higher than theincidence rate of common group,there was significant differencebetween them. It prompted there was relationship betweenchromosomal polymorphism and reproduction abnormality. The malefemale ratio was great disparity,the posible reasons were the variantof chromosome Y can be found in male only or it was the result ofsystemic and random error. 2. The detection rates of chromosomalpolymorphism in every kind of couples with reproduction abnormalitywere higher than the incidence rate of common group,there wasstatistical significance between them. It indicated the relativity ofchromosomal polymorphism and reproduction abnormality ulteriorly.3.The detection rate of chromosomal polymorphism of the groupwhose gestational fetus were lost during the first trimester was higherthan the groups whose loss occurred during the mid and trimester,there was significant difference between them. it revealedchromosomal polymorphism correlates with the loss of pregnant fetusevidently , and it effected on the commitment of embryonicdevelopment mostly. 4.The detection rates of chromosomalpolymorphism of the groups whose negative reproduction occouredfor three times and more than three times are higher than the groupswhose negative reproduction occoured for one time and two times,there was statistical significance. With the time of negativereproduction increasing , the detection rates of chromosomalpolymorphism of the couples with negative reproduction increased.The result showed the relationship of them were horizontal. 5.Studysindicated that heterochromatin abnormality may influence the pairing,synapsis and disjunction of germocyte chromosome during maiosis,effect on the formation of gamete,induce reproduction abnormalitysuch as the loss of pregnant fetus,infertility and sterility,the birth ofdefected infants,and so on at last. By the control of gene expression, itcan influence cytodifferentiation. It can also make caryocinesia errorby dosage effect,and leads to embryonic developmental anomaly.Even more it can make some genes related with generation silencebecause of PEV,and bring all kinds of reproduction abnormality.Conclusion:1.The detection rate of chromosomal polymorphismof the couples with reproduction abnormality was higher than theincidence rate of common group,and the same to the groups of theloss of pregnant fetus,infertility and sterility,and the birth of defectedinfants. The result showed there was relationship betweenchromosomal polymorphism and reproduction abnormality. 2.With thegestational age prolonging, the detection rates of chromosomalpolymorphism of the couples whose gestational fetus were lostdegraded. It indicated chromosomal polymorphism correlated with theloss of pregnant fetus evidently,and it effected on the commitment ofembryonic development mostly. 3.With the time of negativereproduction increasing , the detection rates of chromosomalpolymorphism of the couples with negative reproductionincreased. It revealed the relationship of them were horizontal.