Abstract: To test whether the protein Cldn4 (Claudin 4) plays a role in promoting or inhibiting tumor progression in pancreatic cancer, pancreatic cancer cells PANC-1 were selected as the cell model for phenotype investigation. Overexpression and knockdown of Cldn4 stable cell line were established for tumor malignancy phenotype, cell migration and proliferation, and evaluation in pancreatic cancer. Wound healing and transwell assay were selected for evaluation of tumor metastasis ability. MTT statistics indicated the cell proliferation capacity. Experiment results show that Cldn4 inhibits the migration of PANC-1 but has no significant effect on proliferation of PANC-1. Cldn4 plays an oncogene role in pancreatic cancer.