Recently, any text or data file has come to be transportable through the Internet with a personal computer. It is, however, restricted by selection of monitoring point to lay the cable because the personal circuit is generally used in case of continuous type environmental monitors. This is the reason why we have developed an environmental monitoring system that can transmit radiation data files on the Internet. Both 3“φ×3” NaI (Tl) detector and Thermo-Hydrometer are installed in the monitoring post of this system, and the data files of those detectors are transmitted from a personal computer at the monitoring point to Radioisotope Resarch Center of Osaka Univirsity. Environmental monitoring data from remote places have easily been obtained due to the data, transmission through the Internet. Moreover, the system brings a higher precision of the environmental monitoring data because it includes the energy information of r-rays. If it is possible to maintain the monitors at remote places, this system could execute the continuous environmental monitoring over the wide area.