Active rubber inter-planting as well as simple management of naturally occurring regeneration are common in smallholder rubber plantations in Sumatra and provide a way of indefinitely prolonging the life cycle of those plantations. Those permanent forestlike plantations have interesting ecological functions such as being a refuge for biodiversity, providing a permanent soil cover and contributing to the regulation of watercycle. In such systems rubber seedlings grow under much lower light level than in normal plantation conditions where seelings are planted in a open field after slash and burn. The aim of this study was to explore the acclimation potential to low light levels of rubber seedlings and how this acclimation is achieved. This was done by comparing growth and physiological characteristics of seedlings grown under different shading intensities (0;, 55;, 75;and 88;). Parameters measured were photosynthetic response to light intensity (light response curve), leaf chrolophyll content (a and b) and nitrogen content, leaf specific mass, leaf area, stomata density, maximum stomatal conductance, total dry matter accumulation, shoot-root ratio, leaf emission rate and leaf life span. Adaptation of rubber seedling was affected by included changing in the physiological as well as the biochemical and morphological response. The most suitable light intensity for rubber was 0;-55;.