The effect of the strain gradient on the onset of adiabatic shear instability in gradient - dependent particle reinforced metal matrix composites is investigated by using of linear perturbation analysis in this paper . the analytical results demonstrate that high strain gradient produced by the reinforcing particle will provide a strong a deriving force for the onset of adiabatic shear instability in mmcp 结果表明:增强颗粒的加入,改变了基体材料的微结构,并在基体中诱导了高的应变梯度,而这种高的应变梯度为mmcp的失稳提供了强大的驱动力,使其更易发生绝热剪切变形局部化失稳。