Objective To observe the effect of acupoint injection with bacillus calmette-guerin polysaccharide nucleic acid （BCG-PSN） applied in the summer on immune function and onset in the winter in bronchial asthma （BA） patients. Methods Totally 145 BA patients were included in the summer （from July to September） and randomized into the research group and control group

with 73 and 72 in each. The research group was given acupoint injection with 0.5ml BCG-PSN on bilateral Zusanli （ST-36） and Dingchuan （Panting Stabilizer） point. The control group was given intramuscular injection with BCG-PSN 2ml. Both groups were given treatment three times weekly and ten times as one treatment course. The treatment lasted for 3 courses. The asthma control test （ACT） score and immunoglobulin E （IgE） content were observed before and after treatment. The ACT score was evaluated in December of the treatment year and March of the following year. Results The ACT scores in both groups were significantly increased after treatment （P<0.05）

especially in the research group （P<0.05）. The IgE contents in both groups were significantly decreased after treatment （P<0.05）

especially in the research group （P<0.05）. Conclusion BCG-PSN acupoint injection in summer can effectively reduce BA attacks in winter and spring by increasing the ACT score and decreasing the IgE content.