Abstract: Objective To observe the anti-tumor effect of elemene tricarbonyl rhenium-188 complex(ETRC) on small cell lung cancer(SCLC) bearing nude mice model, and also its biodistribution, tumor targeting features. Methods ETRC was synthesized from β-elemene, which is a active ingredient in Chinese herbal medicine. Twelve SCLC bearing nude mice were infused ETRC through tail vein. The radioactivity of tumor and diferent organs were measured in various time phase. And %ID/g was calculated. All 20 mice models were divided into four groups randomly, concluding ①Physiological saline infusion group;②Elemene infusion group; ③¹⁸⁸Re infusion group; ④ETRC infusion group. Twenty four days after infusion, the volume and weight of tumors were measured and analyzed. Results Six hours after infusion of ETRC, the highest radioactive uptake(6.35±0.33) %ID/g was found in tumor mass. Ratio of tumor/blood was 2.59, ratio of tumor/liver was 4.07 and ratio of tumor/spleen was 3.87. The volume and weight of tumor in four groups were:groups ①:(2.945±0.567)cm³,(5.438±1.232)g; groups ②:(1.860±0,263)cm³,(4,876±0.621)g; groups ③:(1.861 ±0,896)cm³,(4.691 ±1.595)g; groups ④:(0.601±0.152)cm³,(1.602±0.194)grespectively. There was significant difference between ETRC infusion group and each of other groups. Conclusion ETRC can effectively depress the growth of tumor and it is a promising agent for the treatment of SCLC.