The development of the Northern key economic region of Vietnam is one of the main motivations for the economic development of Vietnam. The analysis and selection of appropriate directions for the region is very important for the overall development of this region and the nation. This paper uses input – output model (I/O), an effective quantitative tool with the purpose of offering a scientific basis for key sectors selection, investment areas need to be prioritized for the development of the Northern key economic region. The input – output model, which are used in this study, is the expansion intra-regional I/O table with non-competitive type. It is non-competitive because it makes an explicit distinction between intra- regional produced and imported products (including: domestic import and foreign import). Such a distinction provides a better reflection of the use of intra - regional production technology and inputs in the production of output in other regions (or other countries).