Both temporally and Spectrally resolved fine structures of 90° lateral 3/2ω0 harmo-nic emission were experimentally observed. The existence of 3/2ω0 harmonic filaments isattributed to the 3/2ω0 harmonic radiation emitted from neighborhood of the bottom ofmoving filament, about nc/4 away from it. The double hump structure with intensered hump of laterally emitted 3/2ω0 spectrum can also be explained by Doppler correc-tion besides the thermal correction due to fast moving TPD process occuring in the unstable filaments. Estimation of both red and blue shifts using our simple model is wellconsistent with experimental results. Experiments showed that the 3/2ω0 emission wasobviously suppressed by using broad band laser owing to more uniform illumination on the target surface and broad band effect. These may be promissing for superhot electron suppression.