Abstract: A proper weight matrix is used to improve the NewtonRaphson algorithm for the electrical impedance tomography image reconstruction,and a weighted NewtonRaphson algorithm is proposed.The new weighted algorithm can overcome the defect of baddistributed resolution for reconstructed image by using original NewtonRaphson method.This kind of defect is from illcondition of inverse problem and some mathemetical and physical factors such as injecteds current,electrodes disposition,geometrical position of pixel etc.Compared with the simple NewtonRaphson algorithm,the image reconstructed by the weighted one is much better while the computation amount is almost not increased.The algorithm for computation of the weight matrix is also discussed in detail.