Abstract: Objective To investigate and discuss the effect of metastin on inhibiting the capacity of metastasis and invasion in highly metastatic nasopharyngeal carcinoma SUNE-1-5-8F cells. Methods ①The SUNE-1-5-8F cells' were treated with different concentration of metastin(10² nM,10³ nM,10⁴ nM).Contrast the cells before and after treatment.Finally,the capacity of metastasis and invasion were tested by transwell assay.②Forty female mouse were randomly dividend into metastin group and control group.Both were injected with 2×10⁶/ml.SUNE-1-5-8F cells under the right armpits.Mouse in metastin group were injected with 1.17 mg/kg metastin at day 2.The tumor inhibition rate,metastasis inhibition rate and life extension rate were detected by BALB/c-nu nude mouse model assay.The expression of kisspeptin protein was analyzed by immunohistochemistry. Results ①Metastin inhibited the SUNE-1-5-8F cells' capacity of metastasis and invasion in cell assay(P<0.05),whose capacity had a positive correlation with the concentration of metastin.②Metastin didn't inhibit the proliferation of tumor in nude mouse assay(P>0.05),but it reduced the pulmonary metastasis(P<0.05).And metastin influenced the life extension rate of nude mouse(P<0.05).The result of immunohistochemistry showed that the expression of kisspeptin protein of the metastin group was significantly different from the control group (P<0.05). Conclusions ①Metastin inhibits the SUNE-1-5-8F cells' capacity of metastasis and invasion in cell assay,whose capacity has a positive correlation with the concentration of metastin.②Metastin reduces the pulmonary metastasis and prolonged life,but it doesn't inhibit the proliferation of tumor in nude mouse assay.