Objective: To study the expression and clinical significance of calcineurin B homologous protein 2 (CHP2) in gastric cancer (GC) and its effect on malignant phenotype of GC cells. Methods: The protein expression of CHP2 in 297 GC tissue and 198 normal gastric tissue samples were detected by immunohistochemistry. The relationship between the expression of CHP2 and clinicopathologic parameters of GC were analyzed. CHP2-overexpression plasmids and CHP2-interference plasmids were transfected into GC cell lines respectively. Wound healing assay and Transwell experiment was used to detect the invasion and migration ability of GC cells, and cell counting kit-8 (CCK-8) method was used to detect the proliferation ability of GC cells. Results: The positive expression rate of CHP2 in GC was 68.7% (204/297), which was higher in benign margin (34.1%) (31/91), chronic gastritis (59.1%) (13/22), intestinal metaplasia (34.2%) (13/38), low-grade intraepithelial neoplasia (40.0%) (12/30) and high-grade intraepithelial neoplasia (41.2%)(7/17). The positive expression of CHP2 was correlated with tumor, node and metastasis (TNM) stage, lymph node metastasis and distant metastasis (all P<0.05), but not with gender, age, Laurén classification, human epidermal growth factor receptor 2 (HER2) levels, depth of invasion, carcinoembryonic antigen (CEA) level and CEA 19-9 level (all P>0.05). The results of multivariate analysis showed that high expression of CHP2 and TNM stage were both independent parameters for predicting GC patient prognosis (both P<0.05). Interference of CHP2 expression in HGC-27 cells suppressed proliferation and migration significantly (P<0.05). However, over-expression CHP2 in AGS cells promoted proliferation, and migration significantly (P<0.05). Conclusion: CHP2 plays an important role in the development of GC, which is expected to be a molecular marker for patient prognosis and a potential target of targeted therapy for GC patients.