Crystalline ZnO nano-particles were synthesized on Si substrate with and without Au catalyst through chemical vapor deposition(CVD) method with ZnS as the source material for the first time. The growth morphology of ZnO particles is strongly affected by the flow rate, the temperature of the Si substrate and the catalyst. Without Au catalyst, the nano-particles are round in shape with the average sizes in the range of 30-200nm and the density of 10 4-10 9cm -2. In the presence of Au catalyst, ZnO particles grow into hexagonal shape. The average particle sizes are smaller, in the range of 10-100nm, while the particle density becomes larger, in the order of 10 8-10 10cm -2, than those of the ZnO particles grown without Au. Strong and relatively weak photoluminescence peaks around 497nm and 376nm are found for the as-synthesized ZnO nano-particles.