Abstract: The microclimate factors in walnut-wheat intercropping system were measured by using KS4000 handheld meteorological observation station and SUNSCAN Canopy Analysis System.The results showed that microclimate factors in wheat canopy of walnut-wheat intercropping system,such as the average wind speed, temperature,photosynthetically active radiation(PAR) and intercepted photosynthetically active radiation(IPAR) decreased obviously,and relative humidity increased comparing with monoculture system of wheat.As well as the plant weight,grains per spike,grains weight per spike,harvest index,spike number per hectare,1000 grains weight and wheat yield per unit decreased in walnut-wheat intercropping system.Consequently,although the walnut-wheat intercropping system improved the microclimate to some extent,walnut trees shade caused the intercepted photosynthetically active radiation rate lower.At last wheat yield of walnut-wheat intercropping system decreased(P<0.05)comparing with monoculture system of wheat.Therefore,discussing on key meteorological factors in walnut-wheat intercropping system was help for taking adjust measures in field management.

Key words: Walnut, Wheat, Intercropping system, Microclimate, Photosynthetically active radiation, Yield