PCR-SSR is important molecular technology which used popular and effective to study molecular markers in breeding, genetic diversity studies, gene mapping, genetic identification... In this study, the authors analyzed the characteristics of the size of some SSR fragments and evaluated genomic diversity of varieties/clones collected in Tan Cuong commune, Thai Nguyen city, Thai Nguyen province, Song Cau tea Company and Minh Cau commune - Dong Hy district
Thai Nguyen province. Total DNA from the samples is used as a template to perform PCR with specific 5-SSR primer pairs. Amplification results of primers are indicated SSR fragments sequence diversity and diversity of the DNA fragments to be amplified. Using NTSYS version 2.1 software to analysis diversity of DNA fragments amplified by PCR-SSR, research varieties/lines tea is divided into two main groups: Group I included 22 tea samples, divided into 2 subgroups. Subrroup 1 consists of 19 samples (M1, M2, M17, M7, M10, M20, M22, M23, M11, M21, M4, M8, M16, M15, M3, M14, M5, M6, M13), coefficient of variation between them with the remaining 0.412. Subgroup 2 consists of three samples M12, M24 and M25 have different coefficient is 0.252. Group n consists of 3 samples M9, M18 and M19, three samples have largest heritability difference was 0.46 compared with other groups.