Objective To investigate the relationship of the subcellular localization of calcyclin binding protein (CacyBP/SIP) with cell cycle in gastric cancer cell line SGC7901. Methods Double thymidine block was used to synchronize the cell cycle in SGC7901 cells. Flow cytometry was employed to identify the cell cycle synchronization. The localization of CacyBP/SIP protein was observed at the different phase of cell cycle by immunofluorescence staining. The expression levels of total protein and nucleoprotein CacyBP/SIP were detected by Western blotting at different cell cycles. Results Double thymidine block arrested the SGC7901 cells at G1/S phase, then the cells were at S phase in 4h after drug withdrawal. Most of cells got into G2 phase in 8 to 12h after culture and re-entered G1 phase in 16h. Immunofluorescence staining found that CacyBP/SIP was mainly distributed in the cytoplasm at G1/S phase, but then gathered into the perinuclear or nuclear at G2 phase, which indicates that CacyBP/SIP had the characteristics of nuclear translocation of cell cycle dependence. The total expression level of CacyBP/SIP protein had no obvious change at each phase, but the nuclear CacyBP/SIP protein at G2 phase was highest than at any other phases. Conclusion CacyBP/SIP displays cell cycle dependent translocation, and may participate in regulating G2/M phase.