【Objective】 To investigate the predict value of the developmental potential of embryos and embryo implantation rate (IR) and clinical pregnancy rate (PR) with cumulative embryo score (embryo cumulative score

ECS). 【Methods】ESC of 782 IVF cycles and 223 ICSI cycles were calculated

And frequency tables based on ESC and IR and PR were done

then ESCs were compared between pregnant and non-pregnant group. 【Results】The PR was more than 50% when ESC was bigger than 18 and not bigger than 32 in IVF cycles and ESC was bigger than 22 and not bigger than 32 in ICSI cycles

ESC out of these scope causes decreasing of PR. The IR was more than 35% when ESC was bigger than 28 and not bigger than 32 in IVF cycles and ESC was bigger than 26 and not bigger than 32 in ICSI cycles

ESC out of these scope causes decreasing of IR. Two periods of projects showed that ESC of pregnancy group were higher than non-pregnant group (P<0.01). 【Conclusion】ESC can predict the clinical pregnancy rate after embryo transfer

and provide a quantitative clinical standard for embryo selection.