Objective To investigate the effects of transplantation of frozenthawed ovarian tissues on the maturation, fertilization and further developmental potency of oocytes retrieved from grafts. Methods Twenty five New Zealand white female rabbits were divided into three groups randomly, group 1(EM>n/EM>=5), control group; group 2 (EM>n/EM>=10), fresh ovarian tissues were autologously transplanted into the mesometrium; and group 3(EM>n/EM>=10), frozenthawed ovarian tissues were autologously transplanted into the mesometrium. Three months after the transplantation, rabbits were stimulated with folliclestimulating hormone and oocytes were retrieved from antral follicles 13 hours after human chorionic gonadotropin injection. In vitro maturation (IVM) and intracytoplasmic sperm injection (ICSI) were performed to evaluate the fertility potency of the oocytes from frozen ovarian grafts. Results The number of retrieved oocytes in group 2 and 3 were lower than those of the control group (P<0.05); But no significant differences were observed between group 2 and group 3 (EM>P/EM>>0.05); There were no significant differences both in the percentage of immature oocytes and the maturation rate after IVM, among the 3 groups (EM>P/EM>>0.05); Also, among the 3 groups or in each group, the fertilization rate, cleavage rate and blastocyst formation rate showed no difference, no matter the oocytes matured EM>in vivo/EM> or EM>in vitro/EM> (EM>P/EM>>0.05); The blastocyst formation rate derived from oocytes that matured in vitro was significantly lower than oocytes that matured EM>in vivo/EM> (EM>P/EM><0.05). Conclusion