As　the　increasing　of　the　chip　integration　and　adoption　of　large-size　wafers,　the　warpage　problem　is　more　serious　in　WLCSP.　Considering　that　the　die　size　becomes　smaller,　a　full　finite-element　model　with　small　die-size　is　difficult　to　develop.　In　this　paper,　a　quarter　model　and　a　half　general　plane　deformation　(GPD)　slice　model　were　developed　through　finite　element　method　(FEM).　Their　warpage　and　stress　results　were　compared.　Influences　of　different　material　and　structural　parameters　in　molding　process　were　investigated　finally.