the purposes: To know characteristic of cassava varieties Renek, based of harvest uge that different, the weight of diameter, long and amount. The influence the harvest of age toward analyst proximate essence from casava varieties Renek. Determine the age of harvesting of renek cassava varieties for cassava production and starch production This research was compiled by using random design group method (RAKL), and the single factor treatment with different harvest age i.e., 5 , 6 , 7 , and 8 months harvest age. Every harvest were chosen 3 samples, so there are 12 observation samples. The results of this research indicated that the physical and proximate analysis of cassava at each harvest age had different result. This explained that 5, 6, 7, and 8 months harvest age has a different characterization and proximate of starch content along with the growth of cassava varieties of renek.