A nematode recognition of Heterodera glycines was focused on crops of soybean. Valle del Cauca was divided in three zones (northen, central and southern) and 33 farms were visited. The results of the analysis on samples of soils and roots showe that Heterodera glycines is scattered throughout Valle del Cauca, being the southern zone (Palmira, Candelaria and Puerto Tejada) the one having the highest standards in nematode population. Weeds showing a greater frequency percentage were : Digitaria horizontalis, Echinochloa colonum and Leptochloa filiformis, in the northen zone; Ipomoea hirta, Amaranthus dubius and Echinochloa colonum, in the central zone, and Ipomoea hirta, Portulaca oleracea and Cyperus rotundus, in the southern zone , From among the whole species evaluated (weeds, crops, leguminous a n d fodder plants), Glycine max and Phaseolus vulgaris were considered to be susceptible to H. Glycines race 3. Phaseolus angularis y P. multiflora let low population levels.