The flow field of liquified petroleum gas (LPG) -air diffusion flame in a small scale combustion system was measured with a two-dimensional laser Doppler anemometer(LDA). In order to reduce loss of laser output the forward scatter receiving mode was employed.For this reason, the back scatter receiving optical system of two-dimensional LDA from DANTEC company was modified. The practice shows that the forward scatter receiving mode reduces the loss of laser output by a factor of 2 or more,the Doppler signals received are satisfactory.A self-made solid particle generator was used to increase data rate. Solid particles of magnesium dioxide were chosen as scattering particles. The tests verify that this approach is suitable for LDA measurement.