To understand the ecological habits of Culex pipiens pallens in Shandong Province in winter.From December 2015 to January 2016, the overwintering conditions of Cx. pipiens pallens were investigated in Shandong Province.In Shandong Province, in rural districts, the overwintering places of Cx. pipiens pallens were basements, wells and caves; and in urban areas, they were air raid shelters, holes of city walls, sewers and flower cellars.In Shandong Province, the overwintering places of Cx. pipiens pallens are mainly basements and holes, which are under high temperature and humidity, and away from light. Its larvae cannot overwinter.