The　effect　of　cable　loosening　on　the　nonlinear.　parametric　vibrations　of　inclined　cables　is　discussed　in　this　paper.　In　order　to　overcome　the　small-sag　limitation　in　calculating　loosening　for　inclined　cables,　it　is　necessary　to　first　derive　equations　of　motion　for　an　inclined　cable.　Using　these　equations　and　the　finite　difference　method,　the　effect　of　cable　loosening　on　the　nonlinear　parametric　response　of　inclined　cables　under　periodic　support　excitation　is　evaluated.　A　new　technique　that　takes　into　account　flexural　rigidity　and　damping　is　proposed　as　a　solution　to　solve　the　problem　of　divergence.　The　regions　of　inclined　cables　that　undergo　compression　are　also　indicated.