Micromotion kinetics modeling is a key and fundamental issue of ballistic target microDoppler feature research.At presentthe modeling techniques based on Euler anglesEulerRodrigue formula and homogeneous coordinates have some problems such as “gimbal lock”singularity and computational complexity.Quaternion method can express arbitrary rotation in 3D space intuitively and overcome shortcomings of the existing methods by using 4 values instead of the 9 of the corresponding matrix.The quaternion based precession and wobbling microDoppler frequency expressions of ballistic targets are presented after derivation.It simplifies the calculation of target microDoppler in that reducing matrix operations.The simulation results prove that the quaternion based micromotion modeling method is valid and provides a scientific basis for microDoppler extraction and recognition of ballistic targets.