Nd:YAG($lambda$=266 nm, pulse) laser beam was irradiated on the PDMS surface to improve its chemical reaction, wettability, adhesive property. The various surface modification methods of PDMS were already studied using oxygen plasma, ozone and corona discharge. The surface modification using laser has the advantage of the simple experiment that only directly irradiated laser beam on the PDMS surface in the air. After the laser treatment, the PDMS surface was investigated using a contact angle measuring instrument. The contact angle was decreased with a increase of the surface oxygen content. In conclusion, the wettability of PDMS surface was improved by the laser treatment without changing of its bulk characteristics.