A personalized information service method for an information platform having several subscribers is provided. Each subscriber uses a portable device to communicate with the information platform, and the information platform stores several personalized behavior models respectively corresponding to the subscribers. For each subscriber, the personalized information service comprises the steps of collecting operating information related to the subscriber operating the portable device, and transmitting the operating information to the information platform. The information platform analyzes the operating information to adjust the personalized behavior model corresponding to the subscriber.