For a more comprehensive study on the influence of different factors on the shear strength of palm reinforced clay, the paper selected palm sheets with lengths of 2mm and 8mm and added different mass ratios (0.25%, 0.50%, 1.0%, 2.0%) and aspect ratio (1∶ 1,1∶ 2,1∶ 3,1∶4) into the clay. A slow shear test was measured to palm reinforced soil directly.The results showed that palm can improve the cohesion and shear strength of clay soil in Shanghai, meanwhile palm has no influence on internal friction angle;in the direct shear test, the optimal reinforcement is 0.50% and the best aspect ratio is 1∶ 3; The peak shear strength and cohesion of the palm with length of 8mm are both better than the one with 2mm long. The paper pointed out the short of palm reinforced soil as well as the practical engineering problems faced at present.