We performed the analysis of native peptides pool of gametophores, protonema and protoplast cells of the moss. To reduce endogenous proteolytic activity we used an acid extraction buffer with a mixture of plant protease inhibitors. All the actions were performed on ice. After the proper sample preparation, the extracted peptides were identified with use of tandem mass spectrometry on the basis of protein database uniref100, taxon Physcomitrella patens.