In order to investigate agrammatism in right-handed crossed aphasics (RCAs), the speech characteristcs of 4 RCAs were compared with those of 3 left-handed crossed aphasics (LCAs) and 8 Broca's aphasics. The two crossed aphasic groups (RCA and LCA) involved both fluent and non-fluent types. It was believed that agrammatism could be attributed neither to articulation difficulties nor to prosodic disorders.     While the agrammatic patients displayed good abilities in manipulating vocabulary representing semantics, they had poor syntactic knowledge. In speech production, they produced the sequences of content words without functional words more often rather than make errors in syntactic manipulations.     The characteristics of agrammatism in RCAs and LCAs were mutually similar, As a result, the dissociation between vocabulary and syntactic knowledge observed in these cases might be attributed to the abnormal lateralization of language functions.