Adjoint-free　calculation　method　is　proposed　to　compute　conditional　nonlinear　optimal　perturbations　(CNOP)　combined　with　initial　perturbations　and　model　parameter　perturbations.　The　new　approach　avoids　the　use　of　adjoint　technique　in　the　optimization　process.　CNOPs　respectively　generated　by　ensemble-based　and　adjoint-based　methods　are　compared　based　on　a　simple　theoretical　model.