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The phase relations at the 600 degreesC and 700 degreesC isothermal sections of the ternary systems R-Co-B for R Nd, Pr and R = Sm, Cd respectively were summarized in this paper. For Rm+nCo5m+3nB2n, two new types of compounds R3Co13B2 ( R = Pr, Nd, Sm, Gd, Dy, Ho, Er, Y) (m = 2, n = 1) and R5Co19B6 (R = Pr, Nd) (m = 2, n = 3) were synthesized by utilizing the principle of structural combination. Their crystal* structures and easy magnetization direction were determined by X-ray powder diffraction, and structures were refined by the Rietveld method. The Curie temperature T-C, saturation magnetization M-s and anisotropic field H-A of the new compounds were measured using a vibrating-sample magnetometer, an extraction sample magnetometer and M(H) - H curves of samples in different magnetization directions respectively. The T-C and M-s of Rm+nCo5m+3nB2n increase with increasing values of m at a given n value. H-A increases with an increase in n when m is kept invariable. The effects of the substitution of Ni for Co on the magnetic properties of Nd13Co15-xNixB2 were also investigated. It was found that T-SR decreased monotonously as the concentration of Ni increased, and at x = 3 the easy magnetization direction becomes axial at room temperature. The relations between crystal structure and magnetic properties of Rm+nCo5m+3nB2n and the possible routes of synthesizing permanent magnetic materials are also discussed.