We are studying an autonomous water sensing robot that can move on water surface. The robot moves to desired points and keeps its location for water environment monitoring. The monitoring applications employed for the identification and analysis of environmental changes in aquatic areas such as lakes and seas have gained interest in recent years. Water environment monitoring by using autonomous robots has advantages, such as reducing the risk of accidents caused by navigating to the monitoring points, enabling continuous monitoring, and collecting a large amount of water environment data. The purpose of this research is to develop a water environment monitoring system with a robot that enables long-term and continuous observation and demonstrates a new monitoring method.