The paper presents new formal language for describing multiagent systems, which are collections of interacting, autonomous agents. The research work includes the description of the fundamental features of agents (processes) as well as the way they communicate with each other. The language defined in the paper allows describing the properties of systems such as deadlock, termination, and fairness. Two main results are presented for the defined logic: non-compactness of the semantic conse quence relation and the lack of the deduction theorem. The article is an introducion to further research.