One of the major concerns of natural rubber consumers is the variability of some of the technical properties of NR due to its vegetative origin. Previous work done at IDEFOR/DPL to obtain an insight into, and reduce, this phenomenon were focused on ISO type microanalysis of dry rubber (from latex or of cuplump) from seven clones which are the most-planted clones in Cote dIvoire. These studies identified three groups of properties, molecular size, vulcanization rate and oxidizability, as being responsible for this variability. A microanalysis technique has been developed to determine molecular size by Steric Exclusion Chromatography (SFC). This assists in the comparison of rubber behaviour before and after the processing step. The current studies are with both the more promising clones planted in Cote dIvoire and the amazonian clones resulting from the IRRDB 1981 Expedition and use this technique. The first results from this work are presented and the outlook for it is assessed.