The purpose of this study is to estimate the effects of genetic and environmental factors on the carcass grade of Hanwoo steers. The data of 38,886 Hanwoo steers slaughtered from 2015 to 2016 were used. A bivariate ordered probit model was used to consider the endogeneity between meat quality and meat quantity grades. The results indicate that the meat quality grade was higher in autumn than in summer, and higher in clustered region than in non-clustered region. In addition, as the expected progeny difference of marbling score increased, the meat quality grade increased. As carcass weight increased, the meat quality grade increased, and as rearing period increased, the meat quality grade increased, whereas the meat quantity grade decreased. The results also indicate that the meat quantity grade was higher in spring and lowerin autumn and winter than in summer. The meat quantity grade decreased when expected progeny difference of back-fat thickness increased, whereas the meat quantity grade increased when expected progeny difference of eye-muscle area increased. The results of this study may contribute to the government’s Hanwoo production policies and provide useful information regarding Hanwoo feeding for improving farmers’ income.