Abstract:Korean pine mixed forest is one of the most important vegetation in northeast China. It plays an important role in alleviating global climate change, guaranteeing the wooden product supply and maintaining biological diversity. Four plots located at the 52thand 54th compartments, Dongdapo nature preserve, Jiaohe, Jilin province, were analyzed by using the univariate distribution (UDSSP) and bivariate distribution (BDSSP) of stand structural parameters and nonlinear model (NLM), with the purpose to clear the relationship between coniferous and hardwood species, which may contribute to the reconstruction of lowproduct secondary forests. These stands stood for Fraxinus mandschurica Rupr. and Pinus koraiensis Sieb et Zucc. mixed forest and Juglans mandshurica Maxim. and P. koraiensis mixed forest, respectively. The results showed that: (1) Most conifers were in a state of high mixture and dominance, and only few belonged to the middle or inferior plants; the majority of hardwoods were also intensely surrounded by other species and the ones with different dominance showed an equal number; (2) Many individuals were intensely mixed and randomly distributed at the same time, the slightly difference was conifers biased towards regularity when compared with hardwoods; (3) Most conifers were randomly distributed and had advantage on sizes, while few medium or inferior trees had the same pattern. Hardwoods with different dominance were randomly distributed and only few were regular or clump; (4) Their diameter classes were well expressed by power function or exponential functions. These features revealed that spatial patterns and diameter distributions were closely similar within different types of forest stand and differed from conifers to hardwood species groups.