Diamond circular saw blade has become the most important cutting tool during the stone machining and has been used widely in cutting stones.Because the ratio of diameter to thickness is usually larger than 200,the bending ability of blades is limited.Diamond saw blade could also cause vibration in high speed cutting.Once the frequency is close to other external excitation frequency,resonance will occur and the amplitude will increase rapidly.In order to measure lateral vibration of diamond saw blades,the lateral vibration problems at different speed range is studied by using laser displacement sensor.Through analyzing the curve between the speed and the amplitude,the variation rule between the lateral amplitude and the speed of saw blade is concluded.Resultsshow that amplitude of saw blade will increase with the increase of saw blade revolution and remains small in working revolving range.When revolution of saw blade is out of its working range,the amplitude will increase quickly.As with the saw blades with inner diameter of 100 mm,at revolution of 300 r/min,amplitude of blades with outer diameter(OD)2300 mm is 3.5 times as much as that of blades with OD 800 mm,and amplitude of blades with OD 3600 mm is 7 times as much as that of OD 800 mm blades.