Abstract: A rapid method of total RNA of Schistosoma japonicum adult worm isolation by single step extraction with an acid guanidinium thiocyanate-phenol-chloroform mixture is described. The method provides a pure preparation of intact RNA and can be completed within several hours. It is particularly useful for isolation of RNA from minute quantity of parasite material. Analysis on agarose gels electrophoresis reveals that the RNA preparations show a distinct band comigrating with 18S rat brain RNA and without large rRNA species. The large rRNA is in vivo nicked. The absence of a band at approximately 26S presumably reflects post transcriptional processing of the large rRNA.