The invention discloses a conductive composite material with resistance positive temperature coefficient and an over-current protection element. The conductive composite material with resistance positive temperature coefficient comprises: (a) at least one crystalline polymer base material, accounting for 20-70% volume fraction of the conductive composite material with resistance positive temperature coefficient; (b) a conductive filler, accounting for 30-80% volume fraction of the conductive composite material with resistance positive temperature coefficient, grain diameter of the conductive filler is 0.1-10Mum, and volume resistivity of the conductive filer is not more than 300Muohm.cm, the conductive filler is dispersed into the crystalline polymer base material, and the conductive filler is a solid solution. The over-current protection element prepared by utilizing the conductive composite material with resistance positive temperature coefficient comprises two metal foils, and the conductive composite material is arranged between the two metal foils. The invention has the advantage that the over-current protection element prepared by utilizing the conductive composite material with resistance positive temperature coefficient has low room temperature resistivity, good resistance reproducibility and PTC strength.