Smallholder natural rubber area covers 3 milions ha in Indonesia, among it 2 million ha are rubber agroforests (locally called "jungle rubber") in Sumatra and Kalimantan. These rubber agroforests are the most widespread complex agroforestry system in Indonesia combining production (however productivity is low) and environmental benefits, as well as a certain biodiversity conservation, due to agroforestry practices. Beside being the key to Indonesia's future competitive advantage in natural rubber production, a workable strategy to raise productivity of these rubber smallholders also could play an important role in both poverty alleviation and environment conservation. The "jungle rubber" system is a low-input agroforestry system in which rubber competes with the regrowth of the natural forest. The system is inexpensive and requires little labour to establish and maintain. From the viewpoint of environmental conservation, a rubber jungle with a planting scheme similar to a secondary forest has a positive value, because its habitat is good for environmental conservation. Its good hydro-orology characteristics will resist erosion and enrich plant biodiversity. It positively supports the "green movement", which has acquired a lot of interest from big industrial countries who are also the major consumers of natural rubber. The Rubber Association of Indonesia (GAPKINDO) in collaboration with the International Center of Research in Agroforestry (ICRAF), Southeast Asia Program and CIRAD-CP-TERA (France), have been conducting o -farm trials with participatory approach and economic analysis of improved smallholder agroforest system, funded by a grant from USAID, as well as socio economic surveys in order to identify pros and cons of RAS technology adoption (improved Rubber Agroforestry Systems) . The network has been developed in West Kalimantan (Sanggau and Sintang), Jambi (Muara Bungo) and West Sumatra (Pasaman). The objective is to manage the rubber jungles more intensivel