Clone diversification in Cambodia is the main topic of the rubber development to answer the need of planters. The APIP project (Agricultural Productivity Improvement Project) was financed by World Bank. The Small Rubber Research Component (SRRC) acted on a completing manner with the PHF-AFD project to develop a national plan for rubber development. Comparative clone tests on different localizations showed the good behavior of clone IRCA 18, PB 260 and RRIM 600 for girth and yield characteristics. Fertilizers affected the girth of the trees during immature period. Fertilizer did not affect the yield per tree, but yield per ha was higher because the number of tapping trees was higher at the opening. Clone characterization on site is one of the most important steps for studying the most interesting plant material around the country even in the new areas. This is quite good news to envisage seriously a clone in the country where clone GT 1 is mainly planted in smallholdings.