The aim of this study was to evaluate diversification of medicinal plant resources at the Go Thap Special National Monument site in Thap Muoi district, Dong Thap province. The study was carried out through field trips and plant sampling from 50 standard squares (20 m x 20 m) with typical ecosystems. As a result, 335 medicinal plant species belonging to 243 genera, 100 families, 59 orders and 3 phyla (Polypodiophyta, Cycadophyta and Magnoliophyta) were collected. Of 335 collected species, 31 highly-conserved valuable species are threatened at national and international levels. Of which, 2 species are listed in Vietnam Red Data Book (2007), 29 species in the IUCN Red List (2019), and 1 of 29 this species is recorded in the 06/2019 Decree of Vietnamese Government. Total of 10 parts of these medicinal plants are used to treat 26 disease groups. These medicinal plants are found to grow in 6 types of habitats. The life-forms of these found medicinal plants are divided into 5 main groups (Phanerophytes, Chamaephytes, Hemicryptophytes, Cryptophytes, Therophytes) according to Biological Spectrum of the vascular flora (with life-forms spectrum BS = 57,31 Ph + 8,06 Ch + 5,67 Hm + 10,75 Cr + 18,21 Th), in which the group of Phanerophytes are the most dominant. This study contribute imprtant information and bases to the management, medicinal plant resources conservation in the monument site.