Abstract: The paper study the effect of the laser pulse on the size and thickness of the Ptshell nanoparticles prepared by laser ablation in water in different pulses 100, 150, 200 and 250. The structural properties of the prepared samples were analyzed by using a transmission electron microscopy (TEM) and Uv-visible spectrometer. The results showed they are a possibility of preparing the Ptshell with different sizes and thickness surrounding Agcore, where shell thickness ranging from 8.3-20.1 nm and the Uv-vis shown the peak absorption of the Ag core: Ptshell is shifted from 410-388 nm according to increase the number of laser pulses on the platinum target on the collided Ag NPs, indicating that the Ptshell effect will have an influence more than the Ag NPs core.