Abstract: The common issues that affect the working stability and performance of the system, such as the feedback from the canceling speaker to the input microphone, the secondary path effects, the nonlinearity of the physical elements, and the real-time computational ability, are taken as the clues to illustrate the development of the active noise control in ducts. Typical control system arrangements and algorithms are summarized and discussed in detail. At last, the authors point out that the hybrid control structure with strong antijamming ability, the adaptive-robust control algorithm, the neuro-fuzzy control algorithm, and the smart material based impedance control technology are the main trends of research and development.