Abstract: Fifty-four Landrace×Yorkshire crossbred gilts, with initial body weight of （59±4.2）kg, were allotted to 3×2 factorial experiment to study the effects of dietary energy level and source on follicle development, oocyte maturation in vitro and growth differentiation factor 9 (GDF-9), bone morphogenetic protein 15 (BMP-15), LH receptor (LHR), FSH receptor (FSHR) mRNA expression from cumulus-oocyte complexes (COCs) during the pre-ovulatory phase. Three energy levels were 87.5%(L), 100%(M) and 112.5%(H) accounting for NRC(1998) recommended energy requirement, respectively; two energy source were starch(S) and fat(F). Gilts were slaughtered on day 19 after second estrus. The results showed that the number of large follicles were higher for gilts fed H (P<0.05), energy sources had no significant effect on number of follicles in gilts(P>0.05); cumulus expansion and oocyte maturation were higher for gilts fed H (P< 0.05), energy sources had no significant effect on cumulus expansion(P>0.05); oocyte maturation were higher for gilts fed S than that fed F (P< 0.05); L energy level had higher GDF-9 and BMP-15 mRNA expression (P<0.05), energy sources had no effect on BMP-15mRNA expression, starch diets upregulated GDF-9 mRNA expression (P<0.05). GDF-9 and BMP-15 mRNA expression were higher in COCs from small follicle than that from large follicle in all treatments (P<0.01). LHR and FSHR mRNA expression was higher in H (P<0.05), energy sources had no significant effect on FSHR mRNA expression, however, starch diets increased LHR mRNA expression (P<0.05). The results of this study indicate that higher energy level could increase number of large follicle during the pre-ovulatory phase and oocyte maturation, although energy sources had no significant effect on number of follicles, starch diets increase oocytes maturation. The effects of energy level and source on number of follicle and oocyte maturation maybe modulated by GDF-9，BMP-15, LHR and FSHR mRNA.