A method of strengthening glass plate is provided. A plasma treating process is performed on a glass plate so that a surface pore variation of the glass plate after the plasma treating process is reduced relative to the surface pore variation of the glass plate before the plasma treating process, wherein the surface pore variation is a variation degree of surface pores in different unit areas of the glass plate. In the mean time, a melted network crosslinking structure is formed on the surface of the glass plate. Based on the above-mentioned mechanisms, the glass plate is strengthened. The plasma treating process is conducive to strengthen the glass plate whether the plasma treating process is performed before or after the conventional chemical strengthening process.