Continuous-wave (CW) THz generation fromInGaAs based photomixers has been demonstrated by using a tunable dual-wavelength 3-section DFB laser diode as the optical beat source. The wavelength of each lasing mode can be tuned by adjusting currents in micro-heaters which are fabricated on the top of the each DFB section. The CW THz frequency emitted from the InGaAs photomixers is continuously tuned from 0.16 to 0.49 THz.