Abstract: The moss Physcomitrella patens is now often used as a model system in plant molecular biology. ts short life cycle, easy to culture, transformant analysis and allele replacement make it an excellent material for studying plant molecular biology. Some gene targetings have succeeded and the function of these genes has been proved. Tagged mutant library has been established for the further researches of Physcomitrella patens. The ESTs datebase on Physcomitrella patens which contains almost 67 000 ESTs has been established.