The paper presents a dynamic model intervened by urban design for the decision-making of land development intensity, which expresses the inherent interaction mechanism between lands based on the evaluation of land attributes and their similarity relationship. Each land unit is described with several factors according to their condition and potential for development, such as land function, accessibility, historical site control, landscape control, and so on. Then, the dynamic reference relationship between land units is established according to the similarity relationship between their factors. That means lands with similar conditions tend to have similar development intensities, which expresses the rule of the spontaneous urban development. Therefore, the development intensities of the pending lands can be calculated by the confirmed ones. Furthermore, the system can be actively intervened by adjusting the parameters according to urban design or planning intentions. And the reaction of the system offers effective support and reference for reasonable decision. The system with multiple intervention input is not only a credible tool for deriving development intensities, but also a platform to activate urban design conception. Above all, the system as a socio-technical tool integrates the optimization of form, function and environment, and embodies the principle of impersonality, justice and flexibility in the decision of land development intensity. The paper presents a dynamic model intervened by urban design for the decision-making of land development intensity, which expresses the inherent interaction mechanism between lands based on the evaluation of land attributes and their similarity relationship. Each land unit is described with several factors according to their condition and potential for development, such as land function, accessibility, historical site control, landscape control, and so on. conditions tend to have similar development intensities, which expresses the rule of the spontaneous urban development. design or planning intentions. And the reaction of the system offers effective support and reference for reasonable decision. The system with multiple intervention input is not only a credible tool for deriving development intensities, but also a platform to activate urban design conception. Above all, the system as a socio-technical tool integrates the optimization of form, function and environment, and embodies the principle of impersonality, justice and flexibility in the decision of land development intensity.