///The results of zircon U-Pb dating and laser 40Ar/39Ar dating for the volcanic rocks from the Longjiang and Guanghua formations are compared respectively. The two dating methods display a significant close age. Due to its economy and convenience, the laser 40Ar/39Ar dating method would be useful and practicable in the 1:50 000 and 1:250 000 regional field works and other studies.