为了消除对流扩散方程因对流占优引起的数值震荡，本文首先将其转化为特征形式，并利用移动最小二乘基函数，构建了特征线无单元Galerkin方法．再对新建方法进行收敛性分析，分别给出关于支持域半径和时间步长的两种误差估计．最后，分别针对一维和二维算例进行了数值计算，并与有限元法进行了比较．数值结果表明，本文算法收敛性好，可以消除数值震荡，且通过选取合适的罚因子和支持域的无量纲尺寸，计算精度比有限元法更高，是求解对流占优扩散方程的一种有效程数值计算方法．

In order to eliminate the numerical oscillation caused by convection dominant of convection diffusion equation, the equation is transformed into its characteristics form firstly, and then the element free Galerkin method is proposed by using the moving least square basis functions. The convergence analysis of our method is analyzed, and two kinds of error analysis about the radius of the influence domain and time step are derived, respectively. The numerical examples are presented to discuss the comparison the new method with the finite element method as well. The numerical results show that the new method can be used to eliminate the numerical oscillation with a good convergence. Moreover, the accuracy of the new method is better than the finite element method by choosing the optimal penalty factor and dimensionless size. The new method is an effective numerical method for solving the convection-dominant diffusion equations.