Under normal Pinellia sowing density,two intercropping methods including corn wide-narrow rows and equal rows and three corn planting distances including 35,50,and 65 cm were conducted to study the changes of Pinellia ternata growing environment,growth,yield and quality of P. ternate. The land equivalent ratio and interspecies competitiveness under the intercropping system were analyzed. The results showed that the leaf surface temperature,the soil temperature and the canopy light intensity of P. ternata were decreased with the increase of corn planting density in P. ternate/Corn intercropping system. Compared with the control,the leaf surface temperature of P. ternata decreased by 6.8 ℃,and the soil temperature decreased by 4.3℃. whereas the main leaf area,petiole length and SPAD value of P. ternata were significantly (P＜0.05) increased in the intercropping system. The growth index of corn with a 35 cm equal rows plant spacing is the best compared with the control. The main leaf area,petiole length and the SPAD value increased by 4.85 cm2,2.25 cm and 8.5,respectively. The land equivalent ratio in the intercropping system increased. Corn was more competitive than P. ternate. Intercropping corn significantly increased yield and single tuber weight of P. ternata. Under the condition of corn with a 35 cm equal rows plant spacing,the yield of P. ternata was the highest,with an increase of 44% compared with P. ternata monoculture. There is no significant difference in the medicinal quality of P. ternata under the intercropping corn,which meets the requirements of Chinese Pharmacopoeia.