Concerning the last global changes at state international system, we see that the aspects of diplomatic service have rapidly modified its capacity to influence not only at the national level, but also at the international one, too. Therefore, political, economic, cultural and social cooperation have a great impact on nowadays situation, contributing to constructive relations between leaders of states, and also having a really good perspective to strengthening world order. Due to this, the present article is conditioned by different factors, first of all of external ones: the situation of Republic of Moldova in the international context, and the internal one: the relation between the state and its national institutions. We propose to carry out a deep investigation of the diplomatic service activity in the system of state of Republic of Moldova, to determine the concept dimensions of the diplomatic service and state system.