Objective：To investigate the feasibility of diffusion tensor imaging（DTI） and diffusion tensor tractography（DTT） on L4，L5，S1 nerve roots of normal adults and to analyze the diffusion parameters. Methods：DTI and DTT were performed on 20 healthy volun－teers at Philips Achieva 3.0 T magnetic resonance scanner. Fractional anisotropy（FA） and apparent diffusion coefficient（ADC） of the nerve roots（L4，L5，S1） were measured and results of DTI and DTT were obtained. Results：Twenty volunteers were successful recon－structed by DTI and DTT. L4，L5，S1 nerve roots could show clearly on the DTT map. Average FA and ADC values of healthy volunteers （L4，L5，S1） were 0.395±0.146 and （1.288±0.116） mm2/s，0.390±0.122 and （1.297±0.087） mm2/s，0.387±0.117 and （1.294±0.132） mm2/s，respectively. There was no significant difference of diffusion tensor parameters between bilateral nerve roots（P >0.05） and between upper and lower nerve roots（P >0.05）. Conclusions：DTI and DTT on L4，L5，S1 nerve roots of normal adults are feasible. DTI and DTT can show the architecture of the nerve roots and provide quantitative information for further research of the nerve root diseases.