MT1JP was found downregulated in GC tissues and cells. Low expression of MT1JP was significantly correlated with advanced TNM stage and lymphatic metastasis. Gain- and loss-of-function of MT1JP revealed that MT1JP functioned as a ceRNA for miR-214-3p to facilitate RUNX3 expression and then upregulated p21 and Bim levels suppressing GC cell proliferation, invasion and migration, and promoting apoptosis. Furthermore, MT1JP overexpression suppressed tumor growth and inhibited the expression of miR-214-3p and proliferation antigen Ki-67, but increased the expression of RUNX3, p21 and Bim in vivo. Our results suggest a potential ceRNA regulatory network involving MT1JP regulates RUNX3 expression by competitively binding endogenous miR-214-3p in tumorigenesis and progression of GC.