Abstract: [Objective] To study the correlation of stone cell content and POD4 gene expression in rough skin pear and normal skin fruit of mature Korla Fragrant Pear in the hope of providing molecular basis for improving the fruit quality.[Method] Rough skin fruit and normal skin fruit of Korla Fragrant Pear during the mature period were used as materials,and the firmness and the content of stone cell were determinated.Total RNA was extracted from fragrant pear fruit pulp,quantification expression of POD4 gene was determinated by Real-time fluorescent quantitative polymerase chain reaction (qRT PCR),the correlation of the firmness and the content of stone cell and quantification expression of POD4 gene were analyzed.[Result] The content of fruit stone cell was between 0.4 and 0.52 gram,pear firmness was between 245.22 and 314.71 PA and quantification expression of POD4 gene in mature pear was between 106.89 and 743.29.[Conclusion] The content of stone cell in rough skin fruit is 1.3 times than the normal skin fruit,the hardness was 1.28 times,POD4 gene expression was 6.59 times.The correlation between the content of stone cell and the quantification expression of POD4 gene was significantly positive (r =0.823),and correlation between the content of stone cell and the fruit hardness was positive (r =0.783).The correlation between quantification expression of POD4 and fruit firmness was positive (r =0.770).Therefore,the level of expression of POD gene can be used as a reference index for the identification of the content of stone cell.