In this paper, first of all, I tried to demonstrate how collaborative acivities are socially organized. In paticular, I focus on the issues on how people organize the unit of activity or the boundary of context and on how such organization of contexts comes into being socially visible depending on various resources such as configuration of participants' bodies and tools, devices or makers of conversation, and juxtaposed representations in a collaborative activiy. Regarding this issue, I do not only discuss the theoretical view point of situated approach but also conduct the intearction analysis in the coordination center of distribution and exhange of frozen seafoods. Second, I demonstrate how tools and technologies are embedded in a collaborative activity. According to my interaction analysis of collaborative activity in the coordination center of distribution and exchange of frozen seafood, tools and technologies are embedded in a natural history of events. For example, the representation in a monitor does not show anything without being embedded in a natural history of events exactly like a score itself does not display anything for a player without embedded in actual emsemble. Further, the use of one tool is embedded in a series of tools use. Finally, since the use of tools and technologies is always embedded in a course of actions, the use of tools comes into being resources for reciprocally displaying what each participant is doing by using tools.