This study was designed to determine the effect of High Rumen Undegraded Protein (HRUP) supplementation on estrous response and profile progesterone hormone in early lactation dairy cows under Indonesia tropical environment. The experiment was conducted with twelve early lactation Friesian Holstein cows divided into two groups. Six cows were used as a control group and other six cows as HURP group. Both control and HRUP group obtained basal diet with forage to concentrate ratio 60:40 (DM basis) but different concentrate composition for each groups. Rumen undegraded protein for control group was 27.47% and HRUP group was 32.78%. Feeding twice daily, morning and afternoon. Water was given by ad libitum. The observed variable were feed intake, estrous response and concentration of progesterone hormone. Data obtained were examined by t-test analysis, except estrous response analyzed descriptively. The result showed that 100% estrous response value was normal and the comparison of progesterone hormone on 1st, 5th, 10th, 15th, 17th, 21st and 26th day between control and HURP group was 0.13±0.02 vs. 0.13±0.04, 0.26±0.24 vs. 0.20±0.08, 0.13±0.03 vs. 1.72±2.23, 0.10±0.04 vs. 1.72±3.77, 0.09±0.02 vs. 3.66±3.76, 0.09±0.01 vs. 0.66±0.80 and 0.12±0.03 vs. 1.20±1.08 ng mL–1. It was concluded that HRUP supplementation on early lactation dairy cows could not increase the concentration of profile progesterone hormone. However estrous response value as well as estrous indication and behavior was normal.