Pure NN-dimethylformamide (DMF) and DMF-water mixtures are studied by molecular dynamics (MD) simulations. An OPLS all-atom force field is used for the simulation of DMF, revealing the local order and formation of the weak hydrogen bond of C-(HO)-O-..., and TIP5P is adopted for the simulation of water and is compared with the latest X-ray and neutron diffraction experiment. Solution properties of DMF-water mixtures are investigated using radial distribution functions (RDFs) and hydrogen bonding properties. A significant composition dependence, which is attributed to the prevailing influence of the strongly polarizable amido of DMF and the clustering feature of water, is observed in the simulation. In addition, NMR experiments of DMF-water mixtures are used for the discussion of the hydrogen bonding effect. The results of the simulation are adopted to explain the NMR experiments by hydrogen bonding analysis. As a result, the magnetic anisotropy of the amido group is considered to play an important role in the chemical shift.