Abstract: As people-centered city building advances, urban planning can no longer remain confined to "investing in things". It must better "invest in people" through spatial and institutional arrangements. Yet this demand still faces multiple obstacles in current planning practice. This article constructs a cognition- decision-action framework to explain these obstacles. At the cognitive stage, the people who live in cities and their development needs are often abstracted and averaged. At the decision-making stage, clear rules are lacking for ranking and balancing the multiple values behind "investing in people" and "investing in things". At the action stage, existing institutions and instruments of territorial spatial planning are not sufficiently adapted to translate values and goals into implementable spatial actions. These three mechanisms interact with one another, reducing people-centered planning to familiar rhetoric and weakening its practical force. The article therefore proposes three pathways: shifting, in cognition, from an abstract "average citizen" to fine-grained identification of people in specific contexts; establishing, in decision-making, value-ordering rules oriented toward public well-being and equity; and promoting, in action, coordinated transformation of the territorial spatial planning system in plan content, hierarchical transmission and governance mechanisms, so that values can be translated into institutions and space.