Objective To investigate the effect of kiss-1 gene expression and overexpression on the proliferation of rectal cancer cells. Methods Human rectal cancer SW620 cells were cultured and randomly divided into 3 groups: blank control group (untransfected), experimental group (transfected with pIRES2-Kiss-1) and negative control group (transfected with empty pIRES2 vector). Immunofluorescence staining and immunocytochemical staining were used to observe the expression of kiss-1 in SW620 cells of rectal cancer. Western blot analysis was employed to examine kiss-1 expression in SW620 cells transfected with piRES2-kiss-1 gene. CCK-8 and MTT assays were used to detect the effect of transfection on SW620 cell proliferation. Results The immune recombinant plasmid pIRES2-Kiss-1 was successfully transfected into rectal cancer SW620 cells. Compared with the blank control group and the negative control group, the kiss-1 protein was highly expressed in the experimental group, and the difference was significant (P<0.05). After cell culture for 48h and 72h, the numbers of SW620 cells in the three groups were significantly lower than that in the blank control group and the negative control group (P<0.05). Conclusion Kiss-1 gene can be expressed efficiently and stably in SW620 cells of rectal cancer, which can effectively reduce the proliferation of SW620 cells in rectal cancer.