Genetic diversity: genetic diversity is the sum of the genetic information carried by all living things on Earth. However, the genetic diversity refers to the genetic diversity within a species, that is, the sum of genetic variation between individuals within a species or among different individuals in a population. Intraspecific diversity is the most important source of species diversity at all levels. Genetic variation, life history characteristics, population dynamics and their genetic structure determine or influence the way a species interacts with other species and with the environment. Moreover, intraspecific diversity is the use and understanding of genetic diversity of a species since ancient times when it was raised by animals and cultivated in plants. But the scientific summary and raised to the theoretical level to systematize Darwin. With the rediscovery of Mendelian's law (1900s), Morgen chromosome genetics and later developed cytogenetics provide experimental evidence for population genetic theory. The method of detecting genetic diversity has been improved and perfected with the development of biology, especially genetics and molecular biology. However, any method of detecting genetic diversity is available in theory or in practice. Their respective strengths and limitations, There is no determinant of a successful response that can completely replace the technical interference of other methods. The degree of genetic variation within the species also determines its evolutionary trend. The genetic diversity of Pinus tabulaeformis in the main peak of Liaoheyuan National Forest Park changed with the change of environment at different elevations. Besides its biological characteristics, the genetic diversity of natural populations of Pinus tabulaeformis in Liaohe source was greatly differentiated. It may also be related to the natural selection of microhabitats at different altitudes and the lack of effective gene flow among populations. Pinus tabulaeformis is a unique species with important economic and ecological value in China. It is of great significance to protect its existing genetic resources or germplasm to further utilize its genetic resources and solve practical problems in the production of Pinus tabulaeformis. The difference of habitats in different altitude areas of Guangalu Mountain in Liaohe River had a great influence on the genetic diversity and differentiation of Pinus tabulaeformis populations. Therefore, in the future conservation and breeding practice of natural germplasm resources, We should pay attention to the scientific protection of wild populations of Pinus tabulaeformis at different elevations, at the same time, introduce and cultivate the wild germplasm resources at different elevations, and cultivate new provenances suitable for cultivation in various ecological environments.