Petrocodon pulchriflorus, a new species of Gesneriaceae is described and illustrated from the limestone area of southwestern Guangxi, China. It is similar to Petrocodon guangxiensis, but can be distinguished by several characters, such as the size and shape of leaf blades, inflorescences and corolla, and the position of stamens. Also the phylogenetic affinity of Petrocodon pulchriflorus is presented based on the plastid trnL-F and nuclear ribosomal ITS sequences.