A series of experiment was conducted to determine the concentrations of progesterone and estradiol and metabolite contents in the serum of 26 Korean native cows raised at Alpine Experiment Station during the period of late pregnancy. Blood samples were collected by jugular puncture from individual cow at 5 day intervals from 30 days prepartum to 5 days prepartum and daily collected from 5 days prepartum to the day of parturition. Progesterone and estradiol concentrations in the serum were analyzed by Radioimmunoassay (R.I.A) method and serum metabolite contents were analyzed by autoanalzer MT II system. The following are summary of the results obtained: 1. Progresterone concentrations during the late preganacy were maintained at high level (5.12-11.70ng/$mell$) from 30 days prepartum to 8 days prepartum and fell rapidly from 5.12$pm$1.07ng/$mell$ at 2 dyas prepartum to 1.48$pm$0.32ng/$mell$ at 24 hrs prepartum. 2. Estradiol levles during the late pregancy increased gradually from 33.76$pm$13.64pg/$mell$ at 30 days prepartum to 92.15$pm$11.91pg/$mell$ at 11-15 days prepartum and increased thereafter sharply to a ranges of 161.76-238.4pg/$mell$ and were maintained at this increased levle until 24 hrs prepartum and decreased to 91.40pg/$mell$ at the parturition. 3. The correlation coefficients were found to be 0.2440 for cholesterol-progesterone relationship and -0.2552 for cholesterol-estradiol relationship, but there were statistically insignificant. 4. The changes in total protein contents during the late pregnancy were similar patterns to those of globulin and were maintained at high level only from 15 days to 5 days prepartum. 5. Glutamic oxaloacetate transaminase (GOT) levels were increased from 59.80$pm$3.56u/$ell$ at 90 days prepartum to 93.32$pm$7.27u/$ell$ at the day of parturition, but alkaline phosphatase levels were remained steady. 6. The levels of blood urea nitrogen, glucose and calcium remained almost constant during the late pregnancy. However, glucose concentration increased around the time of parturition.