Abstract: Oocyte quality directly affects production efficiency of modern assisted reproductive technologies such as the in vitro maturation, fertilization, cultivation of cattle oocytes and sperm injection, embryo transfer and animal cloning. Thus, maternal genes (GDF9, Zar1, Mater and DNMT1) are selected to analyze the relationship between mRNA expressions of these genes and quality of ovine oocyte. This study collects ovine oocytes at GV stage and 12-30 h of in vitro maturation (IVM) respectively, as well as ovine oocytes with the first polar body emitted and not emitted. With the application of quantitative RT-PCR technique, mRNA expression levels of GDF9, Zar1, Mater and DNMT1 of oocytes in the above test groups are tested. It is found that: mRNA relative expression levels of GDF9, Zar1 and Mater at GV stage are the highest (p<0.05), while expression of DNMT1 reaches the highest level at 12 h (p<0.05). With the maturity of oocytes, all gene expression levels gradually decline significantly between 18 and 24 h (p<0.05), while the expression levels of four genes present an upward trend at 30 h (p<0.05). Expression of 4 genes in non-polar body oocytes are all higher than those in polar body oocytes (p<0.05). In the natural bare oocytes, expression of each gene is lower than cumulus-oocytes complex. Thus, the test indicates that GDF9, Zar1, Mater and DNMT1 can be the molecular indicators to determine the quality of ovine oocytes.