The need to introduce modern financial instruments in the development of Ukraine’s economy requires the organization and legal support of various forms of investment activity. State support for investment activities is based on budget investments and is carried out on the basis of budget legislation, but the practice of budget investment shows inconsistencies and inconsistencies in terminology, forms and tools of legal regulation of investment activities. The Government of Ukraine has determined that strong investment activity in Ukraine requires consideration and implementation of modern regulations.
 It is emphasized that there is no concept of “investment budget” in the current legislation, inconsistencies in the legal mechanism of their implementation, as well as analysis of the economic situation in some countries with different levels of gross product. low-income countries, the efficient use of public investment is problematic. It is established that budget investments have a special financial and legal nature, are regulated by financial and legal norms and a definition is provided. The features of budget investments as a powerful tool of state regulation of investment activities are identified and it is determined that the efficiency of investment depends on the economic justification of budget investment and legal support.
 It is proved that the improvement of public investment activity is possible through the use of modern financial instruments, including budget investment, which is implemented by allocating funds accumulated in budgets for specific purposes. It is noted that the effectiveness of budget investment depends on a clear targeting of budget funds, their sufficient volume, the procedure established by law and the powers of investment entities. It is determined that the introduction of budget investment requires amendments to the Budget Code of Ukraine, in particular Art. 2 “Definition of basic terms”. It is proposed to involve local governments and the public in investment activities. The author’s definition of «budget Investment» is offered.