Hydrogen gas does not have any absorption lines in visible light - near infrared ray spectrum. It is hard to get the gas distribution in whole area with any contact sensors. Raman scattering shifts wavelength form the incident light due to material composition. We focused on Raman scattering light from hydrogen gas. Raman lidar is ideal to detect the leaked gas remotely and safely. In this study, Compact Raman lidar has been developed for leaked hydrogen gas detection. The minimal detection limit of hydrogen gas concentration is 1% at the observation range of 0 - 50m. When we expand our project, two directions are pointed. One is the improvement to monitor the atmosphere environment. The improved lidar added monitoring water vapor. The other is to rebuild the system to be easy-to-use and to be easy-to-install. LED based mini-lidar is developed for this purpose.