[en] The authors present the temporally and spatially resolved feature of the side scattered 3ω₀/2 harmonic emission induced by a single laser spot with ten-micron-radius-scale in a preformed laser plasma. The close relation of the harmonic emission with such a small scale laser self-focusing filamentation has been discussed in detail. It is suggested that the side scattered harmonic signal from a underdense region as low as 0.05 n_c may be caused by the Langmuir wave and/or ion-acoustic wave scattering induced by laser dynamic filamentation