We study decay properties of the P -wave charmed baryons using the method of light-cone QCD sum rules, including the S-wave decays of the flavor3F P -wave charmed baryons into groundstate charmed baryons accompanied by a pseudoscalar meson (π or K) or a vector meson (ρ or K * ), and the S-wave decays of the flavor 6F P -wave charmed baryons into ground-state charmed baryons accompanied by a pseudoscalar meson (π or K). We study both two-body and three-body decays which are kinematically allowed. We find two mixing solutions from internal ρ-and λ-mode excitations, which can well describe both masses and decay properties of the Λc(2595), Λc(2625), Ξc(2790) and Ξc(2815). We also discuss the possible interpretations of P -wave charmed baryons for the