Abstract: Waterflooding is a kind of conventional measure for improving production and recovery factor in an oil-field, but there exist some formation damages such as water sensitivity, emulsification, etc. In terms of geological fea-tures of reservoirs and waterflood condition in Turpan-Hami oilfield,laboratory waterflood simulation test is conducted in order to check damages of illite/montmorillonite interbeded minerals to the reservoirs by means of centrifugal tech-nique, scanning electron microscope analysis,X-ray diffraction analysis, fluorescent microscope identification and per-meability detections.This paper proposed an idea that emulsion block in migrated illite/montmorillinite interbededminerals has greater damages to oil reservoirs during waterflooding.