Abstarct: Recently, Diluted Magnetic Semiconductors (DMS’s) due to high ability to produce spin polarized current, has attracted a great attention. The result of research was shown that doping of transition mextal oxide elements in wide gap semiconductor lead to higher Curie temperature. SiC is one of the wide gap semiconductors, which is a good candidate for spintronics. In this work we investigate properties of this semiconductor and the effect of Mn doping on it. Using ultrasoft Pseudopotential plan wave method by PWscf code , the effect of doping concentration of Mn on the magnetic properties of β-SiC (SiC:Mn) was quantitatively investigated. Tt is found that the SiC:Mn with low doing shows stable ferromagnetism. Using the density of states calculation, it is shown that SiC:Mn has half- mextallic properties for doping concentration of 3.13%, 6.25%, 25% due to spin polarization at Fermi level, that is desirable characteristics for realizing spintronic devices.