Abstract: In order to explore the combined effect of fresh alfalfa grass and fresh oat grass on feed intake, milk yield, milk quality and rumen fermentation parameters, in this experiment, 240 Guanzhong dairy goats with similar body conditions and fetal childbirth times（two to three parities）from 24 to 48 months were randomly divided into four groups, with three replicates per group, 20 sheep per replicate. Sheep in the control group were fed the experimental diet with 50% silagecorn, those in the test 1 group were fed the experimental diet with 20% silage + 10% alfalfa grass + 20% oat grass, those in the test 2 group were fed the experimental diet with 20% silage + 15% alfalfa grass + 15% oat grass, and those in the test 3 group were fed the experimental diet with 20% silage + 20% alfalfa grass + 10% oat grass. The preliminary trial period was 15 days and the trial period was 75 days. The average daily dry matter itake, average daily milk yield, milk quality indexes（the contents of milk protein, milk fat, lactose and total milk solids）, and rumen fluid fermentation parameters（pH value, ammonia nitrogen and volatile fatty acid contents） of sheep in each group were determined.The results showed that the average daily dry matter intake, average daily milk yield, milk fat and lactose in the test 2 group were significantly higher than those in the other three groups（P＜ 0.05）, and the content of milk protein was significantly higher than that in the control group and and test 1 group（P＜0.05）. There was no significant difference in pH values of rumen fluid among the four groups（P＞0.05）. The ammonia nitrogen content in the test 3 group and the test 2 group was significantly higher than that in the test 1 group and the control group（P＜0.05）. The contents of propionic acid and valeric acid in the test 2 group were not significantly different from those in the other three groups（P＞0.05）. The results indicated that adding 15% alfalfa grass and 15% oat grass to the diet of Guanzhong dairy goats could significantly improve the digestive performance and production performance, and improve the milk quality of Guanzhong dairy goats.