Secondary porosity generation of clastic reservoirs are mainly associated with dissolution of feldspar, lithic fragment and cements, and the dissoluble force is correlative with fluid compositions. There are three homogenization temperatures data of fluid inclusions of clastic reservoirs in different strata and different wells from upper Ordovician to Carboniferous in west Manjiaer sag in the Tarim Basin. The fluid inclusions are mainly immature oxidation and acid fluids. The contents of inclusions are very different in different wells, strata and rocks. The ions of inclusions hosted in overgrowth zone of quartz are simple, which have low content of compositions. The compositions of inclusions occurring in calcite and minerals hosted in quartz are complex, and the composition varies greatly. The physical properties of reservoir are positive correlate with predominant contents of HCO^-₃、CO^2-₃、Cl^-, and irrelative with NO^-3、SO^2-₄. There are three stages of migration of oil and gas.