Salivary (S)-type amylase (AMY) variants (slow-S variants) which migrate slower than S1-AMY were identified by electrophoretically and named as slow-S1, slow-S2, and slow-S3 from anodal side. Briefly, the tested samples were incubated with or without anti-S-AMY inhibitory monoclonal antibodies, and the slow-S variants were indentified by checking the patterns of electrophoresis for the disappearance or reduction of those AMY bands. Slow-S1 was detected at the same position as pancreatic (P)2-AMY, slow-S2 at about the same position as dominant-P2S, and slow-S3 between P1-AMY and dominant-P2S. The detection rates of these bands were 0.07% (5/7, 234) for slow-S1, 0.17% (12/7, 234) for slow-S2, 0.03% (2/7, 234) for slow-S3, respectively. The cause of occurrence of these slow-S variants is not yet obscured. Further studies are warranted to determine whether hereditary factors, modification by the sugar chain or deamination is associated with occurrence of the slow-S variants.