The main objective was to study the variation in the amino acid (AA) profile of microbial fractions obtained after feeding 4 kinds of dietary protein feedstuffs to Xuhuai Goat. Four goats fitted with rumen cannula were used in a 4×4 Latin square design. And artificial diets were divided into 4 groups according to the nitrogen source: group A (feather meal group), group B (corn gluten meal group), group C (soybean meal group), and group D (fish meal group). Results showed that, yields of microbial crude protein (MCP) varied with dietary protein, and the lowest was in group A (10.765 0 mg/mL), while the highest was in group C (13.975 0 mg/mL) (P<0.01). The microbial AA-N ratio was also alerted by dietary protein. Group C recorded the lowest value, and the opposite was found in group D that recording the highest peak. Further multiple regression analysis showed that AA-N ratio (Y) had a negative/positive correlation with bacteria (X1)/protozoa (X2) group, and the regression equation was: Y=15.469-10.098X1+1.498X2 (R2=0.944). It was also observed that, across all rations, significant differences were found between protozoa and bacteria in AA content for some but not all amino acids. Such as protozoal Val was significantly higher than that of bacterial; while bacterial Lys was significantly higher than that of protozoal. Additionally, within each microbial fraction, significant differences in the content of AA were found among rations. For bacteria, significant difference was detected in Arg only (P<0.05); for protozoa, Met, Leu and His showed significant differences (P<0.05). And the variations of AA were related to the changes of microbial population in some degree. It was concluded that yields, AA-N ratio, and AA profile of ruminal MCP were all affected by dietary protein.