Abstract: The new type of power system is facing the problem of increasing risk of frequency instability due to reduced inertia and decreased frequency regulation capacity. As a flexible frequency regulation technology, demand response (DR) has become an important means to solve the frequency instability of power systems. Firstly, a frequency stability analysis and load frequency control (LFC) model for demand-side resources participating in frequency regulation of interconnected power systems are established. Secondly, a distributed model predictive control (DMPC) algorithm for demand-side resources participating in frequency regulation of interconnected power systems is designed. The prediction model of DMPC controlling DR to participate in frequency regulation of interconnected power systems is derived, and then the frequency regulation controller of DMPC for interconnected power systems is designed. Finally, the impact of automatic generation control mode, DR mode, DR capacity and DR communication delay on system frequency stability is analyzed through simulation. Simulation examples show that the designed frequency regulation controller has good frequency regulation performance and DR can enhance the system’s frequency transient stability.