Abstract:We present a simple system of RoF communication based on electronic-optical frequency modulation(EO-FM) in the article. Optical system software-Optisystem5.0 was adopted. The results of software simulation showe that the simplex -directional 5 Gbit/s data and UHF microwave of 24 GHz were successfully transmitted over 15 km single mode fiber with 0dBm transmitted power, dispersion is 17 ps/nm/km, attenuation is 0.25 dB/km.