The Zn1-xNixO (0 ≥ x ≥ 0.1) system have been synthesized in nanoform by coprecipitation method. Nanostructure features of the prepared samples have been investigated by X-Ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD data reveal that the prepared sample are crystalline and belongs to space group P63mc. The estimated average crystallite size is ranging between 62 nm and 96 nm in agreement with TEM measurements. This also confirmed the nanostructure nature of all samples. The variation of lattice parameters and internal strain, that have been deduced from XRD data, has shown that the solubility limit of NiO in ZnO does not exceed 5% .At 7% and 10% Ni-doped ZnO samples reveal the presence of secondary peaks due to NiO in the XRD spectra. Hysteresis loop curves have been obtained. The saturation magnetization Ms suggests the presence of ferromagnetic behavior, the latter decreases with increasing Ni contents. It is supposed that the presence of Ni-Ni ion interaction suppress the ferromagnetic ordering due to the formation of Ni clusters at high Ni content larger than 7%.