In order to enrich the sources of feedstuffs and reduce the cost for dairy goats, the objective of this study was to evaluate the effects of glutamic acid residue on milk yield and milk composition of dairy goats, and to determine the suitable adding amount of glutamic acid residue in concentrate supplement of dairy goats. A single factor random block design was adopted in this experiment. Forty healthy Saanen dairy goats with similar lactation stage[day in milk:(20±5) days], body weight[(59.80±2.15) kg], parity and milk yield were randomly divided into 4 groups with 10 goats in each group. The nutrient levels of concentrate supplements for 4 groups were basically the same, and the adding amount of glutamic acid residue in concentrate supplements was 0 (control group), 2%, 4% and 6%, respectively. The whole experiment period was 63 days with the pre-test period of 7 days and formal test of 56 days. The results showed that the average daily dry matter intake, milk yield, milk fat percentage, and lactose percentage were not significantly different among all groups (P>0.05). The milk protein percentage at the 35th day of experiment in 2% glutamic acid residue group and 4% glutamic acid residue group was significantly higher than that in control group and 6% glutamic acid residue group (P<0.05), and the milk protein percentage at the 42nd and 56th day of experiment in 2% glutamic acid residue group, 4% glutamic acid residue group and control group was significantly lower than that in 6% glutamic acid residue group (P<0.05). At the 35th day of experiment, the concentration and absolute yield of β-lactoglobulin in milk protein in experimental groups showed an increasing trend, and the concentration and absolute yield of β-casein in 2% glutamic acid residue group and 4% glutamic acid residue group showed an increasing trend, while the concentration and absolute yield of β-casein in 6% glutamic acid residue group showed a decreased trend compared with the control group, but the differences were not significant (P>0.05).The daily absolute yields of milk fat, lactose and milk protein were not significantly different among all groups (P>0.05). It is concluded that the glutamic acid residue can be as the protein feedstuff for dairy goats, and the suitable adding amount of glutamic acid residue in the concentrate supplement for dairy goats is 4%.