In this paper, 26 species of Zygnema are reported from Japan. Among these species, the following 11 are new record to Japan: Zygnema bohemicum Czurda, Z. calosporum Jao, Z. collinsianum Transeau, Z. cylindrospermum (West, W. and G.S.) Krieger, Z. cylindrosporum Czurda, Z. excompressum Transeau, Z. insignisporum Couch, Z. normani Taft, Z. peliosporum Wittrock, Z. spontaneum Nordstedt, and Z. synadelphum Skuja.