In linguistic work, morphology is the study of the rules by which words undergo changes in fo~zn.Morphological classification is the systematic organization of these rules.A detailed account of the morphological classification for Russian is given as used in the National Bureau of Standards project on the mechanical translation of Russian into English.'The account includes the heuristic reasoning from which the classification system ev(Aved, as This report is one of a series describing the present state of the National Bureau of Standards mechanical translation project.The report is devoted entirely to the morphological classification scheme used in the NBS glossary.Subsequent reports will describe the glossary arrangement and various details of the translation program.Most of the classification scheme presented here was developed in 1961 and is based on tentative schemes tried during the period 1959-1961.There has been much interaction between translation program requirements and classification scheme ideas.This work was