In order to raise up success rate of oil & gas exploration in mid-deep sedimentary basin with overpressures, characteristics of pressure response in reservoir compaction and cementation in Dongying formation in Northwestern Bozhong sag was studied, based on a lot of data from thin section, core analysis, grading analysis, SEM, etc. Strong evidence was obtained to testify that detrital reservoir compaction was inhibited by overpressures. In addition, it was not only proved that both carbonate and authigenic clay would be prompted by overpressures, but also indicated that this two types of cementation had disparate characteristics of pressure response in study area. The results showed that primary pore could be preserved about 2.0% as pore pressure was above hydrostatic pressure every 7 MPa in overpressures setting. With response to overpressure, cementations strength changed typically in scarp shape as depth increased: ①Abrupt slope stage from the less depth to 280 m outside of overpressures interface, where cementation strength swiftly increased, was characterized by weak cementation strength, whose cementation was dominated by authigenic clay with about 85%; ②Gentle slope stag from 280 m outside of overpressures interface to overpressures zone, where cementation strength slowly increased, was characterized by strongmiddle cementation strength,whose cementation was mainly occupied by carbonate cementation with over 75%. In normal pressure zone close to overpressures, influenced depth of carbonate cementation with response to overpressures was obviously shallower than that of authigenic clay minerals, the former was about 280 m and the latter was over 430 m. The correlation between residually primary pore and permeability was well in study area, whose coefficient could be near 0.77. It indicated that sandstone with a number of primary porosity could be effective reservoir in mid-deep strata. The research can be taken as theoretical basis for oil & gas exploration in mid-deep strata of sedimentary basin with overpressures.