Structure and magnetic properties of R(Fe1-xNix)11.3Nb0.7 (R=Gd, Tb, Dy, Ho, Er and Y) compounds have been studied by means of X-ray diffraction and magnetic measurements. Substitution of Ni for a fraction of Fe does not change the structure of R Fe11.3Nb0.7, but leads to the contraction of the unit cell volume, the rapidly increasing of the Curie temperature and monotonic decreasing of saturation magnetization. It is notable that introduction of Ni leads to the sharply decline of the easy-axis anisotropy of Fe sublattice and the changes of the spin reorientation temperature Tsr of R Fe11.3Nb0.7 (R=Tb, Dy, Er). A qualitative explanation of the relationship of Tsr and Ni content is given based on the theory of crystal field.