The index gained 3.91 points or 0.28 per cent, on turnover of Bt24 billion.
The Thai market rose in tandem with other Asian bourses, as the yen dropped and Shinzo Abe was approved as Japan's prime minister after promising to promote more stimulus measures. The regional benchmark index was trading less than 1 per cent from its highest close for the year.
Stock analysts predict another bright year for the Thai exchange in 2013, anticipating the composite index to end the year at 1,471 points.