We investigate the effect of nozzle on the particle transport in the SMBI experiments for optimization of fueling in the GAMMA 10 tandem mirror. The diffusion particle during SMBI was evaluated from the emission intensity captured by the fast camera. Compared with the results without nozzle, the particle diffusion was more convergent in the case using the straight nozzle. Simulation results by using Monte-Carlo simulation code (DEGAS) roughly reproduce the 2-D image captured by the fast camera.