Abstract:An improved SDS/acid and phenol method was presented here to be suitable for isolation of totle RNA from dry Grimmia pilifera, a plant contained abundant secondary metabolites. Using chemical SDS as detergent in the extraction buffer, LiCl precipitation of RNA was performed finally after removing of proteins, hydroxybenzene et al. by subsequent H2O—saturated phenol, chloroform and eyewinker. The method yielded total RNA not with integrality and high purity but with simple manipulation and cheapness. It may be applied to other dry plants full of secondary metabolites.