A typical assumption in proxy-based streaming application is that users favor the beginning part of the media object. However, it is observed that any parts of the media content can be the focus of users in interactive scenarios. A new segment-based caching algorithm, named popularity-wise caching, is proposed for interactive streaming. It can cache the hot part media content under arbitrary distribution of media content popularity. Simulations results show that the performances of current segment-based caching algorithms degrade with the increase of user interactivity, while popularity-wise caching can provide lower user startup latency and bandwidth consumption under different user request modes and interactive degrees.