Abstract: There are not only relationships between mother-modules and sub-modules, but also relationships among different sub-modules in a modular organization. Sub-modules cooperate with each other through business trading, information sharing, knowledge swapping, ability crossing, and platform integration, and based on which, a Brick model is built. To go one step further, four kinds of acting modes between different modules are identified: matching, infiltrating, syncretizing, and parasitism, and four kinds of interface are accordingly formed: dyadic interface, embedding interface, symbiotic interface, and avalanching interface. Also different mechanisms of these interfaces are analyzed, respectively. Under the influence of MISP, the design of effectiveness mechanism in the modular organization relies on building the relationship network in a base layer and creating the relational rent in a core layer.