Tomato is a importance vegetable and popular in the world and Vietnam. In order to breed new varieties with hight yied, good quality, the study on genetic diversity in tomato by using DNA markers were needed. In this study, the authors used DNA marker (SSR marker) to analyse genetic diversity of 26 of tomato varieties. 10 SSR marker were used to evailuation. The results showed, only 5 marker were polymorphism. From the PCR products electrophoresis of 5 polymorphism markers, 26 accessions were grouped into 5 clusters with similarity coefficients of 0.7 by using NTSYSpc 2.1 software. The information found in this study is very importance for new tomato hybrid breeding programs.