Under the umbrella of the Canaopt Project financed by French private and public institutions the objectives of this study are to develop new grades (CNR) through the knowleldge of the factors of variability and their impact on properties of Natural Rubber. The production of samples in 5 countries (Vietnam, Thailand, Indonesia, Ghana and Cote d'Ivoire and 3 different grades (TSR 3CV, TSRIO and TSRIOCV) under control postharvest conditions allowed to correlate the process and bulk properties of NR. Mesostructure of NR samples have been studied and curing characterization.