In Hevea brasiliensis, Ethephon is used as an exogenous stimulant of latex production. In downward tapping, it has been shown that its misuse has negative consequences on the metabolism of the latex cells of the tree. However, little is known about the impact of this downward tapping practice on latex-producing metabolism in upward tapping. The aim of this study was to determine the effect of stimulation in downward tapping on the latex-producing metabolism in clones PB 217, when the trees are subsequently tapped up. Study was carried out by monitoring the evolution of biochemical parameters of latex and rubber production. From this study, it was found during the last two years of downward tapping that in PB 217 clone, the optimal metabolism of latex production was obtained with 13 Ethephon stimulations per year. When subsequent tapping is done upward, the stimulation frequencies of the trees greater than 4 times per year in downward tapping have a negative impact on the latex-producing metabolism in PB 217 clone of Hevea brasiliensis. However, in cumulative production over the 10 years of downward tapping added to the 2 years of upward tapping, it is the frequency of 13 stimulations per year in downward tapping which is the highest.