This experiment was carried out to investigate the effect of slope exposure and sowing season on the dry matter yield of three different legume-grass mixtures at alpine area. The experiment was allocated as a split plot design with three replications on the south-and north-facing slope. The main plots were sowing season, spring and fall, and subplots were alfalfa-, red clover-, and white clover-grass mixture. The experiment was undertaken over a period of 35 months from April. 1986 to October. 1988. The results obtained are summerized as follows: 1. Total DM yield and DM yield of legume according to slope exposure were higher on the south-facing slope than on the north-facing slope. 2. Total DM yield and DM yield of legume according to sowing season were higher in spring than in fall. 3. Total DM yield according to mixture was the highest in redclover-grass sward regardless of slope expourse and sowing season, but DM yield of legume in white clover-grass sward.