This paper presents a new multi-axle-steering tractor and trailer model which both tractor and trailer with an actively steering wheel. The aim of this study presents an theoretic analysis of the lateral dynamics for the system using the symbolic manipulation MACSYMA. In this paper a linear analysis is used. The performance characteristics considered including the lateral acceleration effect in steady turning, and the steering algorithms for tractor and trailer front wheel are investigated using the zero sideslip angle criteria. More work is needed to evaluate the practicality and the implementing for the system.