Keywords: 
• cash forestry /
• Camellia oleifera /
• oil content /
• seed maturity /
• climatic condition /
• soil parent material

Abstract: Oil content in Camellia oleifera fruits and seeds is an important economic trait. Multiyear and multi－site investigations，sampling and analyses have identified the factors influencing oil content，such as genetic quality，seed maturity，fruiting number，and soil parent materials of a seeded C. oleifera plantation. Based on single tree－based mean values，variation ranges and variation coefficients in the oil content of either fresh fruits or dry kernels，strong and stable variations in oil content of the fruit and seeds among individual trees were found. Studies on the relationship between seed maturity and oil content as well as that between fruiting number and oil content showed that seed maturity had a positive effect on oil content and fruiting number had a negative effect on oil content，the latter of which has been confirmed by a regressive analysis. Also except for extreme drought in one or two years，there was no obvious relationship between climatic conditions during fruit development and oil content. Seed oil from trees grown on limestone or purple sandy soils rich in calcium was relatively high. Thes conformed with results outside China that showed tree－oil crops preferred calcareous soils. ［Ch，2 fig. 4 tab. 11 ref.］