Abstract： Objectlve To examine the metaphase Ⅱ spindle and chromosome configurations of human oocytes cultured for different times after thawing.Methods Using slow-cooling and raid-thawing protocol combined with 0.3 mol/L sucrose and 1.5 mol/L 1,2-propanedio 1(1,2-PROH)to cryoprotect human mature oocytes(n=102),the 64 survival oocytes without abnormal zona pellucida and cytoskeletal were randomly assigned to three groups after thawing:group A:culture 1 hour(n=20),group B:culture 3 hour(n=22),group C:culture 5 hours(n=22),the fresh oocytes served as control group(n=18).Immunocytochefifical staining and fluorescence microscopy were used to assess the morphology of the metaphase Ⅱ spindle and chromosome.Results (1)The normal spindle rates of groups A,B and C were 10％(2/20),46％(10/22)and 41％(9/22)respectively,significantly decreased compared with control group (83％,15/18;P＜0.05).The rates of absent spindle in group A(45％,9/20)was significantly higher than control group(6％,1/18;P＜0.01).Also,the rates of absent spindle in group A was higher than groups B (14％,3/20)and C(14％,3/20;P＜0.05).However,no significant differences were observed in groups B and C(P＞0.05).(2)A significant increase in abnormal chromosome rate was observed in group A(30％,6/20)compared to groups B(68％,15/22),C(64％,14/22)and control group(78％,14/18;P＜0.05).No differences in chromosome morphology were observed in groups B,C and control group(P＞0.05).Conclusions The cryoprotectant protocol leads to a deleterious effect on the organization of the meiotic spindle and chromosome at MⅡ stage.The 3-5 hours post-thawing incubation could permit restoration of the meiotic spindles and chromosome.