Objective To evaluate the anti-tussive effect of a total alkaloid agent extracted from Papaver Somniferum L. on simple chronic bronchitis of which the syndrome was counterflow ascent of lung qi according to traditional Chinese medicine (TCM). Methods Randomised, double blind method, placebo control and add on design were applied. Forty-five patients with counterflow ascent of lung qi of simple chronic bronchitis were randomly divided into two groups: treatment group (n=21) with alkaloid agent and control group (n=24) with placebo. Results The incidences of obvious coughing in treatment and control groups were 66.67% and 70.83% (P=0.763 3) respectively. The cough alleviation time of patients was 14.64±16.30 h and 15.12±15.28 h (P=0.795 6) respectively. The loss of cough rates on the third day was 28.57%, 16.67% (P=0.337 7) respectively. The average scores decreased were 4.29 and 2.88 (P=0.054 8) respectively. Conclusions The study indicates that total alkaloid agent extracted from Papaver somniferum L. has no significant anti-tussive effect on patients with counterflow ascent of lung qi of simple chronic bronchitis treated with cefaclor sustained release capsules simultaneously. The trial was interrupted by the advice from experts who disagreed with the selection of drug indication.