An increasing impact of system modeling in software development facilitates a vision of software development methodology. Currently one of the leading positions has OMG and its solution for system abstraction, modeling, de-velopment, and reuse – Model Driven Architecture (MDA). A key component of system modeling under principles of MDA is Unified Modeling Language (UML), which defines several kinds of diagrams and their notation. System modeling is an important part of system analysis and design, where MDA pro-poses to use means of automatic code generation. UML offers to use system presentation as interacting objects and offers to model two kinds of object inter-action diagram, namely, sequence and communication. The paper focuses on in-vestigation of analysis, modeling, and design of object interaction and discusses the ability to increase the level of formalization in modeling of object interaction.