Objective To explore the in vitro spermostatic effects and the mechanisms of ceritinib,a novel candidate from the active compound pools previously screened for the regulation of sperm function.Methods The vigor sperm of human and mouse were incubated with ceritinib for 20seconds,and the sperm motility was evaluated by computer assistant sperm analysis (CASA).The integrity of the sperm plasma membrane and the survival ratio of sperm was assessed by hypo-osmotic swelling (HOS) assay and SYBR-14/PI staining.The damage of sperm plasma membrane was detected by electron microscope.The cytotoxicity of ceritinib to VK2/E6E7,End1/E6E7 and Ect1/E6E7 cells was measured by CCK-8 assay and fluorescent staining.Results The minimal effective concentration (MEC) of ceritinib to (5-10) × 106/mL human sperm within 20 seconds was (74.87 ± 31.46)μmol/L,which was significantly lower than the MEC of nonoxynol-9 (219.75 ± 20.89) μmol/L measured in the same condition.The time-dose related spermostatic effects of ceritinib were measured by CASA system.Ceritinib was able to damage sperm membrane and caused sperm death with HOS and SYBR-14/PI staining.With electron microscopy,the sperm membrane was observed to be ruptured,and the heads and tails of sperm were separated by ceritinib.Ceritinib was also able to damage the epithelial cells.Conclusions Ceritinib has acute spermostatic effects and potential contraceptive effects.