The new collimation testing technique of a white light beam using vernier Moire fringes of two line or circular gratings with different pitches is presented. We can visually measure the defocusing ($Deltaf$), the divergence angle ($ heta$), and the longitudinal chromatic aberration $(L_{ch})$ of a collimating lens by using the technique. For example, we obtained $Deltaf$= 21.9 mm and $ heta=0.0038^{circ}$ for a testing lens with the focallengthf = 120.0 mm and F-number of F/2.4. The longitudinal chromatic aberration $L_{ch}$ of another testing lens withf = 65.0 mm, F/1.6, and the Abbe number V = 64.1 for the incident wavelengths of $lambda_1=480 nm and lambda_2=640 nm$ is easily measured by same technique. It is found that the measured value $L_{ch}=1.59mm(pm0.01mm)$ is well agreed with $L_{ch}=1.58mm(pm0.01mm)$ obtained by the autofocus method.