Abstract: In view of oil reservoir heterogeneity,the study of chromium gel flooding system was carried out.The results indicated with the increase of polymer concentration and the number of crosslinking agents,the gelling time decreased.With the increase of polymer concentration and crosslinking concentration,the gelling time and gelling strength rose.The gelling stability went up with the increase of polymer concentration,while increased first then declined later with the increase of the crosslinking agents and coagulants concentration.Performance evaluation results of the preferred gelling system indicated the gelling time and the gelling strength increased first then declined later as the mineralization degree increased.With the increase of p H,gelling time grew,and gel strength increased first then dropped later.The system was resistant to scour,the ultimate recovery improved 21.26% on the basis water flooding,and reflected good flooding effects in heterogeneity stratum.