An all-optical modulated millimeter-wave(mm-wave) signal generation scheme with the tunable carrier frequency based on continuous wave(CW) injection locking of direct modulation distributed feedback laser diode(DFB-LD) is proposed.When the ON-OFF keyed(OOK) data stream directly modulates the DFB-LD,the output transient wavelengths of "0" and "1" bit in laser are different owing to the frequency chirp.As a result,if the CW light injection locks the DFB-LD for the duration of "0" bit,the blue shifted DFB laser and the injected CW light still maintain coherence at the time of "1" bit,and the two tones then beat together at a high speed photo-detector for mm-wave signal generation.We experimentally implement all-optical up-conversion from 2.5 Gbit/s directly modulated optical data to 30 GHz,40 GHz,50 GHz and 60 GHz mm-wave optical signals.The scheme has a simple structure,with no external modulator or radio frequency(RF) local oscillator,and it is low cost for optical mm-wave signal generation in optical/wireless hybrid system.