The advantages of intercropping and the effect of above-ground and below-ground interactions between the two crops in a maize/garlic-sprouts intercropping system were investigated by comparing of the effects of mono-cropping and intercropping, and comparing intercropping where the root system was separated by plastic film (FS) or meshwork (MS) compared to controls with no root separation (NS). The results showed that the land equivalent ratios (LER) of both economic yield and biomass were greater than 1. The economic yield of intercropped maize and garlic-sprouts were 933 kg?ha-1 and 3620 kg?hm-2 higher than those of mono-cropped maize and garlic-sprouts, respectively,which was a clear yield advantage. The combined effect of the above-ground and the below-ground interactions between the crops resulted in an increase in the absorption of N，P and K by maize and the absorption of N，Ca and Mg by garlic-sprouts. The intercropping environment was more beneficial to the growth of garlic-sprouts and caused a reduction in the quantity of weeds compared to the mono-cropped garlic-sprouts.