The experiment was conducted to determine effects of different dietary protein sources on blood concentration of amino acids in the left rumen vein and vena mesenterica of Xu huai goat. Three goats with an initial body weight of 33 kg were fitted with left rumen venous cannula and vena mesenterica cannula, and fed four different protein diets in a design of 4×3 mis-classification Latin square, which contained soybean, cottonseed, rapeseed and distiller’s dried grain soluble (DDGS), respectively. The CP contents of four diets were 13% and the ratio of concentrate and forage was 3∶7. The results showed that the concentration of fluid amino acid（FAA）and peptide amino acid（PAA）in the left rumen vein was the highest in the protein diet containing soybean. Higher levels of glutamic acid and arginine were found in FAA in left rumen vein, and higher level of phenylalanine in PAA. The concentration of FAA and PAA in vena mesenterica was the highest in the DDGS diet. The FAA absorbed in vena mesenterica contained more serine and leucine, and PAA contained more serine, arginine and valine.