The behaviour of starch during tuberization was carried out in order to determine the appropriate yam starch properties for industrial applications. Starch was isolated from "Kponan" variety of D. cayenensisrotundata and submitted to functional properties study. Starch granule size increases with tuber maturation from 23.8 µm at 12 weeks, to 25.1 µm at 24 weeks after planting. Granule shape is the same whatever the degree of tuber maturity. Swelling power and solubility pattern of starch increase with tuber maturation. Starch clarity improved during tuberization as well as gel syneresis. The percentage of transmittance increased during the growth of tuber from 9.96% at 12 weeks to 14.6% at 24 weeks. Past instability is not influenced by the tuber maturity. In general starch harvested at mature state could be used to produce satisfactory starch products.