Abstract: To explore the mechanism and effect of yield increase by mixed sowing of different prismatic barley varieties, multi prismatic variety‘Baodamai 14’and double prismatic variety‘82- 1’which have been promoted in large areas of Baoshan City, are used as materials. 5 treatments are set up with single sowing and mixed sowing. The results showed that mixed sowing sufficiently utilized the space and light energy to increase the yield, the yield of mixed sowing increased by 139.5-719 kg/hm2 compared with the single sowing of double prismatic variety, and increased by 40.5-720 kg/hm2 compared with single sowing of multi prismatic variety. In yield components, the effective spikes of mixed sowing were similar with that of the single sowing of double prismatic variety (the maximum effective spikes appeared in the single sowing). The actual grain number of spikes increased by 7.8-10.7 compared with the single sowing of double prismatic variety. 1000-grain weight increased by 1.2-5.5 g compared with single sowing of multi prismatic variety. Moreover, mixed sowing could reduce lodging. The best ratio of basic seedlings with mixed sowing (double prismatic variety‘82-1’and multi prismatic variety‘Baodamai 14’) was 6:4 (convert into seed weight≈7:3).