This study was performed to analyze carcass quality grades of pigs according to sex, marketing year, backfat thickness and carcass weight. Data from a total of 60,189 heads were collected. The results obtained were as follows; the significant difference was found in the carcass quality grade between female and male (barrow) pigs (p<0.001). The pork grade 1+ was high in females, whereas the pork grade 2 was high in barrows. The significant difference was detected between marketing years in the carcass quality grade (p<0.001). The pork grade 2 was significantly high prevalence in the group of backfat thickness with less than 15 mm (86.7%), while the prevalence for the upper class grades (1 and 1+) was high in the group of 15-19 mm (p<0.001). The prevalence for the pork grade 2 was highly shown in the group of carcass weight with more than 71-77 kg (79.0%). However, the pork grade 1 was highly appeared in the group of over 78 kg. In conclusion, pigs for marketing to improve high meat quality should be appropriately managed in optimum production systems with consideration of backfat thickness and carcass weight etc.