Urbanization in Northeast China is influenced by population, economy, and space. By analyzing 34 cities, it was found that the economy plays the biggest role in urbanization, but there is room for improvement in the development model. The region is in a stage of accelerating urbanization, but there is a lack of coordination between population, economy, and space urbanization. Cities along the Ha-Da railway show a trend of shrinking economy and space urbanization from south to north, while population urbanization increases. The development of urban agglomerations is strongest in the Central Cities of Liaoning Ha-Chang City Group. The findings provide valuable insights for guiding urbanization in Northeast China.