The tip of Noto peninsula of Ishikawa Prefecture is regarded as a hotspot of endangered species of aquatic insects, such as Dytiscus sharpi and Cybister lewisianus, inhabit in paddy fields or irrigation ponds. To reveal habitat use of aquatic insects, we compared the aquatic insect fauna between conventional farming method (CFM, 4 paddies) and new labor-saving method (LSM, 4 paddies) from 2010 to 2011. LSM is different to CFM as follows; water of LSM will be kept until before harvesting, meanwhile CFM changes water level to dry up paddies. Aquatic insects were scooped with fine mesh in a plastic frame. The flame was set 20 times along with ridges of each paddy. To compare species composition among management types and yearly variation, we analyzed the data by using the ordination method called detrended correspondence analysis (DCA, with CANOCO Version 4.55). Totally 38 species of aquatic were observed and Dytiscidae, Hydrophilidae and Haliplidae were dominated. DCA analysis showed that the species compositions were relatively similar in each agricultural method and the difference among methods was explained in axis 1. The yearly variation could be explained by axis 2. Diversity was more in LSM than in CFM and breeding observation of rare diving beetles in LSM. That is possibly rerated to water management.