Abstract: In this paper genetic diversi. ty and differentiation of 3natural populations of Tamarix chinensis, one of the main predominated tree species in Yellow River Delta, were studied using random amplified polymorphic DNA (RAPD) techniques. It was showed that amplifications with 26RAPD primers yielded 105analyzable loci and the proportion of polymorphic loci accouoted for 40. 07%. Nei’s gene diversity (h), Shannon diversity index (I), Coefficient of genetic differentiation (Gst) and gene flow were 0. 4061, 0. 5917, O. 0507and 9. 3564, respectively. AMOVA showed that there was a relatively low level (7. 17%) genetic differentiation among the populations. Therefore, a relatively high level of genetic diversity existed in species. The majority of genetic variation occurred in populations. A high level of gene flow happened among populations. Genetic distance was remarkably correlated with geographic distance.