Abstract: To investigate the dynamics of soil enzymatic activity with regard to the combined effects of oat variety and different fertilizer and legume mixtures, an orthogonality experiment has been conducted in an alpine area. The experiment consists of three factors (oat varieties, fertilizer and legume mixtures) and four levels made up of (1) four oat varieties: Avena sativa cv. Qingyan No.1, A. sativa cv. Lena, A. sativa cv. Qinghai 444, A. sativa cv. Qinghai; (2) four fertilizer mixes: CK₀, urea (75 kg/ha)+NH₄H₂PO₃(150 kg/ha), organic manure (1500 kg/ha), urea (37.5 kg/ha)+NH₄H₂PO₃ (75 kg/ha)+organic manure (750 kg/ha); and (3) four Vicia sativa sow mixture rates: 0 kg/ha, 45 kg/ha, 60 kg/ha, 75 kg/ha. The results showed that appropriate combinations of oat variety, fertilizer mixes and legume sow rates can significantly improve soil enzymatic activities. The activities of soil urease, cellulose and invertase were respectively in the range of 400-900 μg/g, 80-180 μg/g and 4-7 mg/g in the cultivated alpine soil. Ranked from high to low, the factors that influenced soil enzymatic activities were first fertilizer mix, then variety, then legume mixture rate. Soil urease activity first increased and then decreased during the growth period, peaking at anthesis; cellulose activity first decreased and then increased, peaking at jointing stage; invertase activity had two periods of increase followed by decrease, with double peaks at the jointing and heading stages. Soil enzyme dynamics were calculated using the relative enzymes activity index and the relative enzyme activity comprehensive index. The highest soil enzymatic activities were recorded in the treatment consisting of the Qinghai 444 or Qinghai sweat oat variety mixed with 45 kg/ha V. sativa and fertilized with 37.5 kg/ha urea, 75 kg/ha NH₄H₂PO₃ and 750 kg/ha organic manure.