For cobalt films deposited and annealed under the non-ultrahigh vacuum conditions of 5 × 10-5 and 5 × 10-6 Torr respectively, a new epitaxy, type C CoSi2, locally grown on (111)Si at 600-850 °C was found. Meanwhile both type A and type B epitaxy were also present and type B orientation dominated over type A and type C orientations. The orientation relationships between type C CoSi2 and the silicon substrate are (001)CoSi2(111)Si and CoSi2 Si. Corresponding to the three equivalent 〈110〉Si directions, three type C variants, having structurally equivalent domains, were grown epitaxially on (111)Si. Only one set of parallel dislocations was observed at the interface C-CoSi2/(111)Si. The parallel dislocations were identified as of mixed type with Burger's vectors of 1/2〈110〉a. The epitaxial growth of type C CoSi2 on (111)Si may be the result of contamination by carbon and oxygen in the cobalt layer.