A new subspecies of Ardisia crenata Sims (Primulaceae), namely A. crenata Sims subspecies obtusifolia Chatan & W. Promprom, collected from Nakhon Pranom Province, Thailand, is described and illustrated. The distinguishing morphological characters between two similar subspecies are discussed. The new taxa is clearly different from the other subspecies in shape, apex, margin, texture of leaf blade, primary rachis of inflorescence and sepal characteristic.