20 good quality varieties were grown in single-cropping late season rice and double-cropping late season rice in 2002 in Changsha and from Dec.15, 2001 to April 20,2002 in Sanya. Milling, apparent qualities and cooked rice elongation of 60 samples of 20 varieties and cooking quality of 33 samples of 11 amongst 20 varieties were tested. Variation coefficients of rice quality traits under 3 different environment conditions were calculated. Quality index of 9 quality traits of 11 varieties was calculated by the agricultural minister standard of the cooking rice variety quality NY/T-593-2002. The result showed that the stability of quality traits, which related to quality index varied with rice varieties. Variation coefficients of rice difference quality traits have great disparity. The percentage of quality traits, which reach standard of the third class, varied with variety and environment.