Objective To investigate the value of ultrasonography in the diagnosis and treatment of caesarean scar pregnancy (CSP) after cesarean section,so as to help clinicians to select proper treatment methods and evaluate therapeutic effects.Methods Retrospective analysis on the clinical data and ultrasonographic features of 27 cases of CSP which were diagnosed by ultrasonography and clinically confirmed in our department from August 2012 to August 2014 was made for the study.Results According to the ultrasonographic features,the cases in the group were divided into the gestational sac type (17 cases) (with a diagnostic accordance rate of 88％) and the mass type (10 cases) (with a diagnose accordance rate of 80％).Total diagnose accordance rate was 85％.After treatment,the sizes of foci,blood flow andβ-HCG values were all decreased.Conclusion Ultrasonography is of important value for the diagnosis of caesarean scar pregnancy after cesarean section,and can help clinicians to select better treatment methods and evaluate therapeutic effects.