Lanzhou's 2025 population is now estimated at 3,430,880. In 1950, the population of Lanzhou was 335,675. Lanzhou has grown by 64,970 in the last year, which represents a 1.93% annual change.These population estimates and projections come from the latest revision of the UN World Urbanization Prospects. These estimates represent the Urban agglomeration of Lanzhou, which typically includes Lanzhou's population in addition to adjacent suburban areas.