Abstract: Such parameters as laser power, laser beam mode structure, focusing spot morphology, etc have a decisive effect on laser processing quality. In order to understand the different processing capacity of different laser device, the high power laser beam for industrial processing, especially the power density distribution on the transverse of focusing point, was measured, providing the basic data for raising laser processing quality. The authors adopted the quality diagnostic instrument of high power laser beam / focula to measure the power density distribution of several typical industrial high power laser beams. The main modes of the measured laser beams are quasi-basic mode, mixed mode and multimode, of which the application fields are given according to the measured results.