Abstract: Objective To determine the effects of macrophage stimulating protein (Msp) on the proliferation, migration and invasion of human non-small cell lung cancer cells PC14. Methods The eukaryotic expression vector for st1 was constructed and transfected into Msp (-) and RON (-) human non-small cell lung cancer cells PC14. The expression of st1 mRNA in PC14 cells was observed by RT-PCR. The expression levels of Msp protein in PC14, PC14-st1 -pEGFP-N1 and PC14-pEGFP-N1 groups as well as the expression of RON in PC14 and SKBR-3 cells were detected by Western blot. RAW264.7 (mouse monocyte macrophage) and SKBR-3 cells were cultured in the supernatant of cells (PC14, PC14-st1 -pEGFP-N1 and PC14-pEGFP-N1 groups) and tested with Transwell microporous membrane, through which the biologic activity of Msp was evaluated by calculating the cell number migrated. The proliferation of PC14 was measured by MTT assay. The capabilities of PC14 to migrate and invade were measured by Transwell chamber and Matrigel invasion tests, respectively. Results The expressions of mRNA and protein of Mst1 in PC14 were stable after transfection with Mst1. Msp (PC14-st1 -pEGFP-N1 group) promoted the migration of RON (+) cells (SKBR-3 and RAW264.7). Compared with PC14 and PC14-pEGFP-N1 groups, the proliferation, migration and invasion of PC14 cells in PC14-st1 -pEGFP-N1 group were inhibited significantly. Conclusion Msp can promote the migration of RON (+) cancer cells in paracrine secretion manner and inhibit the proliferation, migration and invasion of human non-small cell lung cancer cells PC14 in an unknown way.