Fertilization is one of the most important factors that affect growth and yield of rubber tree. It takes a high rate of capital investment for plantation. Regulation on fertilizer quantity or/and ratio among fertilizer nutrients results in remarkable economical and technical impacts on the rubber plantation during the immature period. During the mature period, data are still controversial. This experimental study aimed to evaluate the effects of fertilizer on the latex yield and physiological parameters. After four years of experimentation, results showed that fertilization had a positive effect on the cumulative yield (kg.ha-1) by 4% whereas the rubber yield per tree (g.tree-1) increased by 10%. Physiological parameters of latex cells, sucrose, thiols and inorganic phosphorus contents, were slightly increased by the use of fertilization. This positive physiological change in latex sugar loading and in latex metabolism might be related to yield increase after fertilization.