Sesame( Sesamum indicum L.) is an important oilseed crop in tropical and sub-tropical areas,but recent seed shortages for consumption have occurred. To address this,study objectives were to characterize and classify sesame phenotypic traits; disease and drought resistance; and germplasm constituents( i. e.,oil,protein,and sesamin content) through accession classification using principle component analysis at the Oil Crops Research Institute( OCRI),CAAS. This organization maintains a total of 5,426 sesame accessions,of which 5,218 originated from China( representing 29 provinces,municipalities,and autonomous regions,except for Ningxia,Qinghai,and Taiwan),and 208 derived from 24 countries including Asia,Africa,Europe,South America,and North America. A total of 110 randomly selected sesame accessions and cultivars were seeded at OCRI between May 20 and June 10,2005-2006. All accessions produced 8 to 55 g of seed per plant. All tested sesame accessions were successfully grown at the Oil Crops Research Institute( OCRI),CAAS. Accessions were classified into 4 discrete clusters. Variance analysis and principal component analysis revealed a high degree of variability among the accessions based on phenological,morphological,and reproductive traits. These traits can be used to effectively distinguish accessions and to improve breeding programs for high-yielding sesame cultivars.