This study presents an analysis of floristic composition patterns for limestone tropical forests in Xishuangbanna, which is located in the northern edge of tropical Asia. All trees in four 50 × 50 m plots with diameter at breast height (dbh, 1.3 m) ≥ 5 cm were measured and identified. A total of 998 individuals belonging to 100 species, 74 genera and 31 families were recorded in these plots. Species richness ranged from 18 to 46 species per plot. The most ecologically significant family as determined by basal area and stem density was Euphorbiaceae. Cleistanthus sumatranus and Lasiococca comberi were the dominant species. Total basal area was 33.5 m2 in the four plots, ranging from 7.0 to 10.5 m2 per plot. Comparing tropical forests in this area, this limestone forest showed lower species diversity and higher dominance by Euphorbiaceae. Results from this study will improve our understanding of the community composition of tropical limestone forests in the northern edge of tropical Asia.