The data of 550 beef tattles collected after grading in Seoul Whole Sale Market, NLCF from September, 1995 to March, 1996 were analyzed to estimate effects of sex, carcass weight and some carcass traits on retailed cut percentage. Correlation between lean and supreme meat percentages was 0.741 and correlation between lean and top grade meat percentages was 0.939. For steers, lean meat, bone, supreme meat, and top grade meat percentages were 65.31, 12.80, 15.15, and 37.74%, respectively, which were lower than those of bull which were 67.27, 13.09, 16.09 and 12.41%, respectively. However, fat percentage of 21.88% and rib percentage of 12.41% were higher than those of bulls which were 19.41 and 12.06%, respectively. In cow, bone percentage of 12.30% was low but ratio of muscle to bone of 1.84 was high. The grade 1 of meat quality obtained higher fat yield and ratio of fat to bone than the grade 2 and 3 of meat quality. The grade A of meat yield obtained higher lean meat percentage, top grade meat percentage, ratio of muscle to bone, and ratio of muscle to fat which were respectively 67.03, 39.09, 5.26 and 3.56% than the grade B and C of meat yield.