Abstract: Avena sativa is a widely used forage and green manure in northwestern of Shanxi Province. This experiment was carried out with split- plotex periment design in Shanxi Province in 2013, to research the influence of row spacing and irrigation rate on seed yield components and seed yield of Vicia sativa. The results showed that: (1) As row spacing increased, plant height gradually decreased. At different row spacing, plant height was negatively correlated (R=- 0.8563) with seed yield. (2) The influences of row spacing and irrigation rate on seed yield components and seed yield of Vicia sativa were different. Row spacing had greater effect on seed yield , repro-ductive shoots , florets, and seeds, but irrigation rate had less effect on the above factors. (3) Of the seed yield components, repro- ductive shoots(x₁), seeds (x₂), florets (x₃) were positively correlated (P＜0.05) with seed yield, the correlation coefficients were 0.325, 0.702 and 0.804 respectively. The regression equation was y=269.853+64.102x₁+49.978x₂+5.379x₃. (4) The highest seed yield was obtained when row spacing was 60 cm and irrigation rate was 900 m³/hm².