The objective of this paper is to make conclusions regarding the development planning system in Latvia, as well as to give suggestions for the optimization of development planning system with an aim to promote sustainable development of national economy. As a result an updated and enlarged model of national development planning system is proposed. The proposed model allows to put into practice unified development planning process that connects different term and level planning documents to each other as well as national and EU funding investment planning documents. So the proposed model encourages synergy between investments of different sources, which is of particular importance in the current economical situation when resources for stimulation of economy are limited. In addition the model proposes mechanisms for stronger connection between development planning documents and political guidelines. Moreover, proposed model strengthens the linkages between development and budget planning.