There exists certain angle relationship between human upper limb and vertical direction（or horizontal direction）

when human upper limb moves.Angles between each axes of the three-axis acceleration sensor ADXL330 fixed on the human beings’upper limb and the direction of gravity（vertical direction） can be used to detect the motion gesture of human upper limb.The feasibility of this method is proved by the experiment

in which data are acquired when the sensor is put on the different directions and are processed by using the Matlab software.The results of the experiment are compared with the exact values

and the relative errors are less than 1%

the absolute error is less than 4°.And the motion gesture of human upper limb is detected by putting the sensor on human wrist

the result of which is compared with the result from the high-speed camera system

and the absolute error is less than 5%.The experiment results show that ADXL330 can be used to detect the motion attitude of human beings’upper limb in a range of errors.