Abstract: A method to detect the turnip mosaic virus (TuMV) ondiseased Pseudostellaria heterophylla was established and applied. Specific genetic fragments at different locations in TuMV was amplified by RT-PCR, sequenced, and aligned. The sequence alignment indicated that the fragment was the coat protein (CP) gene of TuMV. Hence, a simple, reliable detection method based on the CP gene sequence of TuMV for the diagnosis on diseased P. heterophylla was established. Using the method, the target sequence was detected in the root, stem, leaf, and flower of P. heterophylla.