The flow field of two horizontal opposed liquid-liquid impinging streams was experimentally studied with the PLIF technology in order to investigate the stability of impingement plane and the oscillation characteristics of stagnation point at various nozzle separations and fluxes. Oscillation period was not regular and frequency concentrated on the low frequency region. While amplitude concentrated on 0.1d-0.5d. When L belonged to [1d

3d] ( where L was nozzle separation and d was nozzle diameter )

amplitude increased with the growth of L

but when L belonged to [3d

5d]

amplitude decreased with the growth of L. The amplitude of impingement plane did not always grow up with increasing flux

which gradually decreased after reaching a peak. The oscillation characteristics of impingement plane and stagnation point were favorable to mixing and mass transfer.