Abstract: The study of the relationship between physical activity and happiness was a major issue related to the reconstruction of the value in physical activity. Eight basic problems were put forward which needed to be solved urgently. Those problems were as follws:what were the notional categories of "physical activity" and "happiness" in the proposition of "physical activity could make people happy"? How many dimensions did happiness from physical activity consist of? Why could physical activity bring happiness to people? How did physical activity regulate the baseline of people's happiness? What was the biological basis by which physical activity could make people happy? What could physical activity bring to people's happiness? How should we judge whether physical activity bring happiness to or not? How could physical exercise give consideration to "health" and "happiness" at the same time? The existing problems and the ideas as well as the future research directions were also pointed out.