Abstract: Competition is increased for water sources with the increase of planting density in maize. This study investigates the effect of planting density on the water content of stalk and root. A field experiment based on a spring maize variety and three planting densities (LD:4.50×10⁴ plant·hm^-2,MD:6.75×10⁴ plant·hm^-2 and HD:9.00×10⁴ plant·hm^-2) was carried out. The result showed that there was a minor effect from planting densities on the water content of stalk in earlier stages,whereas there was a greater effect of planting densities on the water content of stalk in later stages. The average water content of nodal root from the 5th to 7th layers under MD took the first place,which under HD took the second place and which under LD was lowest. The average relative water content of nodal root from 1st to 4th layers under LD took the first place,which under MD took the second place and which under HD was lowest,whereas that of nodal root from 5th to 7th layers under MD took the first place,which under LD took the second place and which under HD was lowest.