Major problem when Thai medicinal plants are used in production process is the similarity of morphology of dried plants. Most of raw material are dried, mashed or ground into a powder that leads to difficulty for identification, and results in obscurity and effect on patient safety. For this problem, identification using molecular markers should be applied. The microsatellite or simple sequence repeat (SSR) marker is one of DNA marker methods that were chosen for identification of medicinal plants in this project. Four species of Thai medicinal plants, Thunbergia laurifolia L., Clinacanthus nutans (Burm.f.) Lindau, Diospyros mollis Griff. and Andrographis paniculata (Burm.f.) Wall. ex Nees were used in this study. The genomic DNA enriched microsatellite libraries of each species were constructed and the microsatellite primers were developed. From this experiment, the 75, 60, 26 and 36 primer pairs of T. laurifolia, C. nutans, D. mollis and A. paniculata, respectively, were designed. These newly developed microsatellite markers will be tested for amplification and polymorphism, and applied for identification as well as genetic diversity of these four medicinal plant species.