Abstract: This paper reviews the theoretical research on stand spatial structure and stand spatial utilization, analyzes the relationship between them, reveals the meaning of stand spatial utilization, analyzes the characteristics of parameters of existing spatial structure and spatial utilization, and put forward the representation index and calculation formula of stand spatial utilization rate. The horizontal space utilization rate is quantified by the sampling method, and the vertical space utilization rate is quantified by the height distribution of each layer of forest on the basis of dividing the main forest layer, succession layer and renewal layer. The findings indicated that the stand space is the space formed by the stand surrounded by trees in 3 dimensions. Among them, the horizontal space is generated by the number of trees, distribution pattern and location relationship, and the vertical space is generated by the distribution of stand height, the range of vertical levels and the number of trees in each layer. The utilization rate of stand space is the degree to which the stand space is filled by trees, which is expressed as the percentage of the stand space occupied by trees. Its theoretical basis is the principle of forest community and population ecology. In the process of stand development, the space size and utilization rate of stand are constantly changing, and the change of stand space structure makes the space utilization rate change. There is a close relationship between them, but the existing stand space structure and space utilization indicators are difficult to quantify the space utilization of stand. The quantitative method of stand spatial utilization rate proposed in this study considers the number and distribution pattern of trees at the horizontal level as well as vertical layers and the number of trees at the vertical level. It is a comprehensive quantitative method and provides a technical reference for optimizing the stand structure. The stand spatial utilization ratio can be used as an evaluation index of spatial structure, which is suitable for quantifying the spatial utilization of forests of different origins. The quantitative results provide a basis for forest structure optimization, decision-making of forest management measures and evaluation of the effect of structure optimization, and have theoretical and practical significance.