Snails are ecologically diverse. The pulmonate taxa are air breathers, can tolerate hypoxia, and are often capable of resisting temporary or seasonal drying. The non-pulmonates use gills to breathe, require oxygenated water to survive, and are rarely able to tolerate drying. Snails have a widely diverse taxonomy, ecology, and physiology. Their basal position in food webs and passive dispersal may make snails potential environmental indicators. We studied the differences in the snail assemblages of different types of marsh wetlands in northeastern China, and explored the possibility that snail species could be used as indicator species for different types of marsh wetlands. In September, 2014 and May, 2015, snails were collected from 17 sites spread across Deyeuxia angustifolia wetlands, Carex schmidtii wetlands, Carex lasiocarpa wetlands, and Carex pseudocuraica wetlands. By collecting them in spring and autumn, we avoided the influence of spawning on the numbers of snails, and reduced identification interference caused by larvae. We collected a total of 4452 individuals, which belonged to eight families, 13 genera, and 17 species. The snails were mainly members of the Planorbidae, Lymnaeidae, and Physidae. The results showed that the aquatic snail assemblages were affected by wetland types. The clustering analysis, non-metric multidimensional scale, and an analysis of the similarities between the snail communities divided them into four cores. These were the Deyeuxia angustifolia wetlands, Carex schmidtii wetlands, Carex lasiocarpa wetlands, and Carex pseudocuraica wetlands. Six snails were indicator species for these four types of wetlands, and the characteristics of these snails corresponded to the hydrological and vegetation characteristics of the different wetland types. Aplexa hypnorum was an indicator for Deyeuxia angustifolia wetlands; Galba pervia, Segmentina hemisphaerula, and Pupilla sp. were indicators for Carex schmidtii wetlands; Succinea sp. was an indicator for Carex lasiocarpa wetlands; and Valvata cristata was an indicator for Carex pseudocuraica wetlands. There were also some differences and characteristic variations in the biodiversity indexes of the snail assemblages between different wetland types. The differences in snail assemblages between different wetland types meant that the effects of vegetation should be recognized when studying the invertebrates found in typical marsh wetlands, and those connected with wetland protection and wetland ecosystem restoration. The snails can be used as one group of indicators (Wetland types). This study also provides a scientific basis and data that can be used to rationally develop and sustainably utilize snail resources.