The effects of using quicklime as a water absorber on polyethylene microporous film under actual production conditions are studied. A twin-screw extruder was used for compounding the CaC03/PE blend into pellets containing LDPE, LLDPE, ground calcium carbonate, antioxidants and lubricant. Two dehurnidifiing methods of hot air and quicklime absorber were used in a production line equipped with a stretching unit. Physical properties of two types microporous film were compared with hydrostatic pressure, SEM, XRD, FTIR EDS and residue on 635 mesh screen analyses. The rnicroporous film with quicklime dehumidifier showed lower hydrostatic pressures on average with much greater variation than with the hot air dryer. The results indicate that adverse effects occur due to the impure ingredients of quicklime and the coarser particles of calcium carbonate which can not be detected by laser particle size analyzer.