In this work, we discussed the importance of system integration for human-system interaction, and analyzed how to achieve system integration in a UbiComp environment, as well as related human factors. There are two human factors discussed in this work, and they are for system and human correspondingly. The former is that users will migrate among different systems to perform interactions, whereas the latter is that the integrated system has to respond as fast as possible when interacting with users. According to the analysis, we proposed an integrated system architecture for human-system interaction in a UbiComp environment. We also analyzed our proposed architecture with other kinds of models, and evaluate their performance.