<i>Betula platyphylla</i> Suk. is one of the most widely distributed species of <i>Betula</i>, the fourth most valuable timber species in north-eastern China and also a common tree species for landscaping. Over the past 30 years, effective progress has been made in genetic improvement and molecular breeding of <i>B. platyphylla</i>. There has been extensive research on breeding techniques, including the collection and conservation of <i>B. platyphylla</i> germplasm resources, provenance trials, intensive breeding techniques, crossbreeding and asexual propagation techniques, ploidy breeding and mutation breeding technology, genome sequencing, gene cloning, transgenic and molecular mechanisms of wood formation. A <i>Betula</i> germplasm resource collection has been established by collecting different provenances, and full-sib and half-sib families. In addition, the geographic variation patterns of <i>B. platyphylla</i> provenances have been revealed, and the provenance division and superior provenance selections made. <i>B. platyphylla</i> flowering and seeding have been improved through intensive breeding techniques. Interspecific hybridization, intraspecific hybridization and parallel crosses were made using fine parents, and <i>B. platyphylla</i> intensive seed orchards have been established. Systems of asexual propagation, including cuttings, grafting and tissue culture have been established. A <i>B. platyphylla</i> tetraploid was successfully constructed and a <i>B. platyphylla</i> triploid seed orchard established. The growth, wood property and resistance genes of <i>B. platyphylla</i> have been cloned. An efficient <i>B. platyphylla</i> transgenic system mediated by <i>Agrobacterium tumefaciens</i> was established, and genes encoding <i>B. platyphylla</i> insect resistance, drought resistance and salt tolerance, lignin synthesis, flowering, hormone transport and balance obtained. <i>B. platyphylla</i> molecular markers were developed and the high density <i>B. platyphylla</i> genetic map constructed. All this research has provided a model and data for the foundation of forest genetic improvement and applied research.