Estimation of Genetic Parameters, Correlation, and Clusterization of Twenty Genotypes of Physic Nut (Jatropha curcas L.). This experiment was conducted at Pakuwon Experimental Station with altitude about 450 m above sea level, Latosol type of soil, and B type of climate, beginning from May 2008 until December 2009. It was aimed to analyze the genetic parameter, correlation, and clusterization of twenty genotypes of physic nut. Randomized complete block design with twenty genotypes of physic nut as treatment and three replications was used in this study. Variable observed were vegetative, generative, and yield characters, and the data observed were analyzed by anova, correlation, factor analyses, and cluster analyses. Results showed that : (1) the genetic variability of number of inflorescence/tree, number of bunchs/branch, number of bunch/tree, number of fruit harvested/tree, and weight of one fruit were narrow. Heritability and genetic advanced of these characters were rather high until high. Selection of these characters can be effective; (2) genotypic and phenotypic correlation of number of inflorescense/tree, number of bunch/branch, and number of bunch/tree were positive significant on number of fruit harvested. Phenotypically, plant height were positive correlated and number of primary branch/tree was negative correlated on number of fruits harvested; and (3) clusterizaton results six clusters. Rescaled distance between cluster I, II, and IV were rather near, whereas between cluster III, V, and VI were rather far as well as if compared to cluser I, II, and IV.