The optical fiber probe technique has been widely used in the analysis of gas-solid fluidized bed phenomena owing to the small size, quick response and flexibility of the probe as well as wide ranges of applicability of the technique as a whole. However, they give us only local information of the fluidized bed behavior and then it is hard to understand the macro phenomena in the fluidized bed. Therefore, multi optical fiber probe system and multifunctional optical fiber probe system were developed to clarify the macro scale analysis of the fluidized bed behavior. Also, a particle image scope consisting of an image fiber and a high speed video system was developed for micro scope observations of solid particles in circulating fluidized beds. In this article, we introduce the basic probe structures, examples of the obtained signals, analyzed flow behavior, single particle motion and particle collision patterns.