OBJECTIVE：To compare the efficacy of lobaplatin / cisplatin combined with etoposide in the treatment of primary small cell lung cancer. METHODS：60 patients with small cell lung cancer were randomly divided into observation group and control group. Observation group was given 30 mg/m2 Lobaplatin injection，adding into 500 ml 5％ Glucose injection，d1，by intravenous infusion for 1 h+100 mg/m2 Etoposide injection，adding into 500 ml 0.9％ Sodium chloride injection，d1-3，by intravenous infusion for 1 h. Control group was given 25 mg/m2 Cisplatin injection，adding into 500 ml 0.9％ Sodium chloride injection，d1-3，by intravenous infusion for 1 h+Etoposide injection（the same dose with observation group）. 3-week was regarded as a chemotherapy cycle. The clinical efficacy and toxicities in 2 groups were observed. RESULTS：There were more than 2 cycles for both groups. There was no significant difference in the total effective rate between 2 groups（P＞0.05），and the incidences of nausea，vomiting and diarrhea in observation group were significantly lower than control group，the differences were statistically significant（P＜ 0.05）. CONCLUSIONS：Lobaplatin / cisplatin combined with etoposide has similar efficacy in the treatment of primary small cell lung cancer，and lobaplatin has better safety.