Abstract: Objective To investigate the effects of KISS-1 transfection on the tumor growth of nude mice. Methods Esophaged squamous carcinoma cell EC-1 was transfected with KISS-1 by liposome, and KISS-1 protein in transfected and nontransfected cells was detected by Western blot. Nude mice were transplanted subcutaneously with EC-1 cells, EC-1 stably transfected with empty vectors, EC-1 cells stably transfected with KISS-1, respectively. The tumor volume and weight were measured. Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were used to detect KISS-1 protein and mRNA level in tumor tissue. Results Expression of KISS-1 protein in pcDNA3.1-KISS-1 transfected cells (1.143±0.218) was significantly higher than that in pcDNA3.1 transfected cells (0.745±0.130) and control cells (0.855±0.184)（P<0.05）. In vivo study showed the tumor growth speed of nude mice in pcDNA3.1-KISS-1 transfected group was significantly slower than that in pcDNA3.1 transfected group and control group. The tumor volume in pcDNA3.1-KISS-1 transfected group (949.42±102.26)mm3 was significantly smaller than that in pcDNA3.1 transfected group (1339.82±72.23)mm3 and control group (1384.04±97.07)mm3（P<0.05）. The tumor weight in pcDNA3.1-KISS-1 transfected group (0.498±0.654)g was significantly lighter than that in pcDNA3.1 transfected group (0.638±0.066)g and control group (0.676±0.108)g（P<0.05）. Conclusion KISS-1 gene can effectually express after gene transfection and may obviously inhibit the growth of the xenograft tumor of nude mice.