Abstract: A method of extracting total RNA from Grimmia pilifera P.Beauv of moss was introducted.The fresh Grimmia pilifera was used as the main materials.The improved SDS method was implied,and the reagent of RNA precipitation was LiCl.The total RNA were successfully isolated from this plant.At the same time,the method was compared with others,it could be find that the total RNA of G.pilifera extracted by the method had clear bands,good completeness,high purity and less DNA contamination.The total RNA is suitable for Reverse Transcription,RT-PCR.