The 12 yield components of 27 late maturing varieties of round grained nonglutinous rice were studied and analysed in this article.The results showed that: (1) the tillers per plant, ears per hole, grains per ear, 1000-full-grains weight, 1000-mixing-grains weight and hight of plant are high yield components. And the higher phenotype values of these yield components take, the higher yield is; (2) the varieties are with higher yield components of tillers per plant, ears per hole,granules per ear,the heredity correlation and heredity contribution are more than others. These varieties can be used for the parents in the high yield breeding of late maturing varieties of round grained nonglutinous rice. The selection can be put into effect in early generation according to grains weight per plant; (3)the late maturing varieties with more tillers, ears, grains per ear and high 1000-grains weight can be directly used as high yield varieties in production of rice. The article also reports the high yield cultivation and management technic.