The article deals with historiographical problem of the financial estimation of emperor Justinian#s building activity. The object of the research is expenses on the strategic and defensive building works in provinces adjoining to Iran frontier. Our research method based on calculation of real build-expenses in well-known Early Byzantine building and logistic practice. As the result of this research the author concludes that the main historical sources and the byzantinists exaggerated both scale of the Justinian#s buildings and expenses for it.