Chronic obstructive pulmonary disease is not only with a globality and high sicken rate,but also with high death rate. The important reason of COPD reiterative outbreak   and   progressing   aggravation   is   the low immunity   function. The treatment   of COPD   with lung and spleen qi weaken in catabatic period should fill weakness and fast Ben which is a very important. Huangqi' character is sweet and warm, turn over to the lung and spleen's route, which have the function of strengthen spleen and rising Yang, benefiting   and   fasting surface, diuresis .Combined with its pharmacology, huangqi can   boost economy's metabolize, anti-tiredness ,adjust and tone up   the economy's immunity   function.This research through the pilot clinic study is in order to explore   the fuction of the huangqi treating effection in COPD with lung and   spleen   weaken   in   catabatic period.    Which include immunity function   ,main sign's change   and 6 min walk .which is in   order to making the COPD's prevention and cure developed. The research's result discovers that huangqi capsule have improving trend on body-fluid immunity and cell immunity and its main signs and 6MWT in COPD with lung and spleen qi weaken in catabatic peri od ,and could do more study in which huanqi capsule on prevention and cure in COPD.