Abstract: Four crossed-breed dairy goats were fed on Thermopsis Lanceolat R.br dry hay powder at dosage of 5 g/kg body weight,blood samples were collected on the 0th, 7th, 14th, 28th, 35th and 42nd experimental day　for examining routine blood indexes, serology enzymology and biochemical indexes. The clinical symptom of the dairy goats was observed every day and the goats were dissected to conduct pathological examination in the end of the experiment. Results showed that the toxic symptom of tested dairy goats occurred in the 30th experimental day with decreased weight, thin body, and coarse fur. In the 41st experimental day, the tested dairy goats began to move abnormally, and suddenly fell down to the ground when being driven away. In contrast to undosed period, the content of hemoglobin and the number of white cells of the tested dairy goats increased significantly (P<0.05) and activity of glutamic-oxalacetic transaminase (GTP) and alkaline phosphatase (APH) increased significantly (P<0.01). Urea nitrogen level in serum decreased significantly (P<0.01) from the 14th experimental day.Pathological changes mainly showed tissue organism was turgescent and bleeding. Histological examination mainly showed vacuolar degeneration in the tissue organism. It was the first time to observe collagenous fiber hyperplasy in liver by ultra structural examination.