Objective : To investigate the extent of meiotic spindle damages in cryopreserved-thawed mouse mature oocytes. Methods : After slow freezing and ultra-rapid thawing using 1.5M dimethylsulfoxide(DMSO), mouse mature oocytes were stained by anti-α tubulin monoclonal antibody. The meiotic spindle and chromosomes configuration were assessed using confocal microscope. The influence of time to post-hCG oocytes retrieval (i.e. 12 hrs vs 17 hrs) was also evaluated. Results : The normal meiotic spindles were observed in 89.8% of post-hCG 12 hrs group, and 80.1% of post-hCG 17 hrs group, and these were significantly lower than that of each unfreezed control. Post-hCG 12 hrs group showed a significantly higher incidence of normal meiotic spindles, compared with post-hCG 17 hrs group. Conclusion : The extent of meiotic spindle damages was significantly increased after cryopreservation in mouse mature oocytes. We proposed that 12 hrs interval of post-hCG oocytes retrieval may be more beneficial.