An analyzing system and a method for evaluating calorie consumption by detecting the intensity of wireless signal are provided. The analyzing system includes a wireless receiving device, a processor and a calorie consumption computing device. The wireless receiving device receives a first wireless signal emitted from a first wireless transmitting device. The wireless receiving device detects a first intensity of the first wireless signal at a first time, and detects a second intensity of the first wireless signal at a second time. The processor obtains a motion information corresponding from the first time to the second time according to the first intensity of the first wireless signal and the second intensity of the first wireless signal. The calorie consumption computing device generates a calorie consumption according to the motion information.