Abstract: The structural feature,reservoir distribution,reservoir physical property,fluid property and current status of exploitation of Zhong'erbei Ng5 unit in Gudao Oilfield were analyzed in this paper.The LB-01 liquid plugging agent used in experimental area was made up of primary agent complex electrolytic agglomerating agent and other auxiliary agents.This water plugging agent was formed by chelation and encasing of soluble glass,agglomerating agent and other auxiliary agents using single-fluid method.After using this plugging agent in 4 oil wells,the average daily output were increased by 10.9 tons,average water cut decreased by 16.6 percents,and accumulated production increased 4 094 tons.