Sesame is one of the oldest oil crops and has an important place in plant evolution. We compared the chromosome types and karyotypes of 8 diploid and 4 tetraploid materials of Sesamum indicum L. and 2 wild species, S. radiatum Schum & Thonn and S. schinzianum Asch. The species significantly differed in karyotype and chromosome variables. S. indicum centromere types were m, sm and st; the average arm ratio (AAR) was 2.11 to 2.25, asymmetric karyotype coefficients (AKC) were 66.05% to 66.99%, and the karyotypes belonged to 2B, 3A and 3B. However, S. radiatum and S. schinzianum exhibited only M and m centromere types; the AAR was 1.09 and 1.08, respectively; AKC was 52.12% and 51.68%, respectively; and karyotypes were 1B and 1A, respectively. Karyotype clustering revealed that the resemblance-near coefficient between S. indicum and the wild species was 0.027 to 0.107, which indicates a remote genetic relationship. Furthermore, seed coat color was more suitable for sesame evolution estimation than was geographic origin. The evolution direction of sesame was from wild species to black cultivars and then white cultivars.