The objective of this study is to investigate the characteristics of aquatic animals, especially fishes in the irrigation and drainage channels, during paddy rice growing. There types of prototype fishways, which are ladder type, flume type and container, are modeled to observe the target fish, migration. Using small fishes named Oikawa Zacco platypus and Baratanago Rhodeus ocellatus, the suitability of migration is carefully evaluated. The main reasons for the fishes to migrate are considered to be the feeding and spawning. It was proved that proposed three types small-scale fishways are all effective for the target fishes to migrate.