Partial squeeze die casting is a special die casting process which combines squeeze technique to conventional die casting. The influence of squeeze pressure (1500-3000㎏/㎠) and time-lags(0.5-2.0sec) on defect control, density and microstructure of ADC12 alloy die casts has been studied by appling partial squeeze die casting to air compressure front housing production. Defect free, maximum density of 2.736㎏/㎤ with sound microstructure of ADC12 alloy die cast has been obtained by partial squeeze die casting technique at the pressure of 2000-2500㎏/㎠ and time-lags of 1.0-2.0sec.