This experiment was conducted to investigate the effects of ratio of corn silage to peanut vine on degradation characteristics of peanut vine in rumen of dairy cows. Four healthy Chinese Holstein dairy cows fitted with permanent rumen cannula were selected to feed different total mixed rations (TMRs), and they had similar body weight and production performance and were in the same physiological status. The ratio of corn silage to peanut vine of TMRs was 3.9:1.0 (group A), 1.2:1.0 (group B), 0.4:1.0 (group C), respectively [dry matter (DM) basis]. The experiment was divided into three periods, each period was conducted to carry out the experiment for each group (groups A, B and C in order). The experiment lasted for 57 d, each period had 15 d pre-experimental period and 4 d sampling period. Ruminal degradation rates of DM, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of peanut vine in 72 h were estimated by the nylon bag technique, and their dynamic degradation parameters and effective degradation rate were figured out. The results showed as follows: 1) effective degradation rates of DM, CP, NDF and ADF was 56.49% to 59.62%, 40.45% to 47.36%, 33.26% to 35.20%, and 36.31% to 37.45%, respectively. 2) Effective degradation rate of DM of group B was significantly higher than that of group C (P<0.05), and extremely significantly higher than that of group A (P<0.01). Effective degradation rate of CP of groups B and C was significantly higher than that of group A (P<0.05). 3) Rapid degradation fraction content of NDF of groups B and C was significantly higher than that of group A (P<0.05). It is concluded that peanut vine has high feeding value. Degradation rates of DM and CP of peanut vine can be efficiently increased when ratio of corn silage to peanut vine is 1.2:1.0.