This study was aimed to compare the change of blood metabolites of Korean female cattle offered either a conventional diet (CON) or a total mixed ration (TMR) diet for 6 mo in prepartum. Twenty-two Korean female cattle (about 27 mo old) were randomly assigned to one of 2 diets and 2 sample t-tests were conducted; CON, concentrate (3kg/hd/day) + rice straw (unlimited) or TMR, (6.6kg/hd/day). The TMR offered per cow per day was composed of concentrate, maize silage, grass, molasses, and rice straw. The DM, CP and TDN intakes were not significantly affected by any of diet groups, but the tendency for higher DM, CP and TDN intakes were observed in the TMR group. The nonesterified fatty acids (NEFA) concentrations in blood were higher for the CON group than the TMR group (566.45 vs. 235.09 uEq/L; P < 0.05). However, the cattle offered TMR had higher blood urea nitrogen (BUN) concentrations (21.69 vs. 10.85 mg/dL; P < 0.05), blood glucose levels (62.73 vs. 40.55 mg/dL; P < 0.05) and blood aspartate aminotrasferase levels (78. 73 vs. 57.18 u/L; P < 0.05) than did the CON group. The creatinine concentrations in blood were similar between 2 diet groups. In this study, Korean female cattle consuming TMR had low levels of blood NEFA, but high concentrations of blood glucose and BUN. This result indicates that feeding TMR is important for Korean female cattle in terms of increasing reproductive efficiency,which has long been recognized as the most aspect of Korean female cattle.