This experiment evaluated the effects of sex and level of crude protein (CP) in diets on nutrient intakes and digestibility, nitrogen retention, rumen parameters, and growth rate of Bach Thao goat. Twelve (6 males and 6 females) Bach Thao goats at 3 months of age with body weight of 12.4 ± 0.06 for female goats and 15.1 ± 0.63 kg for males were arranged in a 2 (sex) x 2 (diet) factorial design in a 150-day experiment with 3 replications per treatment. The diets were 5.5 and 6.5 g CP/kg body weight consisted of elephant grass, soybean extraction meal and copra meal. The nutrient digestibility was determined during the 4th month of experiment. The results indicated that sex and CP level had significant effect (Pmatter (DM), organic matter (OM), CP, neutral detergent fiber (NDF) and acid detergent fiber (ADF). DM intake of female goats was lower than the male (628 vs. 717 g/day) and also lower for the treatment CP5.5 compared to the CP6.5 (619 vs. 726g/day). Similarly, CP intake of females was lower than the males (110 vs.130 g/d) and for CP5.5 compared to the CP6.5 group (111 vs. 129 g/d). When increasing CP in Bach DM, OM, CP, NDF and ADF digestibility (Pand the CP6.5 treatment were significantly higher (P CP5.5 treatment resulting in higher weight gains for male and CP6.5 treatments (P compared to the female and CP5.5 treatments. Rumen pH, N-NH3 and VFAs 3 hours postfeeding were not affected by sex (P>0.05) but differed (PUrinary purine derivative excretion and the estimated microbial nitrogen synthesis in the rumen tended to be higher for the males and the CP6.5 treatment (P>0.05). Result of this study concluded that male Bach Thao goats had higher growth rate and the diet with 6.5 g/CP/kg body weight improved feed and nutrients intakes, digestibility and growth rate.