From the live TV broadcast which follows up the event to the live webcast which leads the event, a distinction could be discovered in the forms of live broadcasts today. With current media convergence, the boundary between TV and new media is further melted and, as a result of media fusion in different situations, some possibility of convergence was shown in the two forms of live broadcast. Does the situation that differentiates the two forms of live broadcasts disappear? How does the change in media forms represented by live broadcast affect the current social interactive system through the redefinition of media situation? The changes and development of live broadcasts was examined in the paper from the "technology-society" perspective by reexamining Meyrowitz’s media situation theory. It is found out that the interactive relationship in contemporary society was reproduced by live media through the randomness of social situations, the hypothesis of social roles and the middle stage social behaviors. Meanwhile, it is pointed out that the disappearance of situations was not resulted from the changes of media forms represented by the live broadcast which, however, break the current social situations into several new individual situations. Based on that, an insight was shed on the development of live broadcast which tends to be more individual after the reconstruction of situations.