X-ray diffraction technology was used to rapidly predict variation in microfibril angle (MFA) in Dendrocalamus farinosus. The results show that there is little variation in MFA with bamboo age from 2a to 5a, and MFA of 3a is at the maximum with the value of 8.521°. The average value of MFA of 2a or 3a is greater than 4a or 5a with absolute differences less than 0.1°. MFA of base, middle and upper position respectively are 8.499°, 8.497° and 8.483° with coefficient of variation about 5%. There is an increasing tendency from the periphery to the inner of bamboo culms. Variance analysis indicates that MFA is highly sensitive to radial position, but insensitive to bamboo age and longitudinal position. The correlation coefficient of longitudinal strength and modulus of elasticity (MOE) is 0.57. MFA was responsible for 35% and 43% of the variation found in longitudinal strength and MOE respectively, which means MFA has a certain extent effect on mechanical properties.