From the time dimension and space dimension, and based on the qualitative analysis, this paper studies the spatial structure evolution of the Pearl River port group using two analysis tools, i.e. the Gini coefficient and concentration factor of cargo flow in the port group when placing it in a long historical period. The results show that the spatial structure of ports of the Pearl River estuary features a staged evolution, the overall trend tends to spread, and the spatial structure of the diffusion process reflects obvious volatility.