ENThe object of the research of the doctoral thesis: the investment climate in Latvia, Lithuania, Belarus cross-border regions (Latvia – Latgale region; Lithuania – Vilnius county, Alytus county, Utena county, Panevezys county, Kaunas county; the Republic of Belarus – Vitebsk oblast, Grodno oblast, Minsk oblast, Mogilev oblast). The subject of the research of the doctoral thesis: quantitative and qualitative differences in the investment climate in Latvia, Lithuania, and Belarus cross-border regions. The research hypothesis: there are a number of significant quantitative and qualitative differences in the investment climate in Latvia, Lithuania, and Belarus cross-border Industrial, labour which are determined by production, labour and tourist potentials, and criminal and social security. The purpose of the research is to elaborate the methodology for assessing the investment climate in the regions, and with the help of this methodology to study quantitative and qualitative regional differences in the investment climate that are determined by the influence of certain factors. In accordance with the research purpose the following tasks of the thesis research have been set: 1. To research into the nature of the concept, the stages in the development and use of the concept “investments” in economic theories; to specify the concept and structure of the investment climate, the factors that influence it as well as statistical indicators that comprise the concept of investment climate.2. To study the world experience in assessment of the investment climate, to classify modern research into the investment climate, to identify strengths and flaws of the methods for research into the investment climate; to elaborate the method for assessment of the investment climate (integral index) at a meso-level in the regions of Latvia, Lithuania, and Belarus. 3. To calculate the integral index of the investment climate in Latvia, Lithuania, and Belarus regions; to classify regions according to the value of the investment climate indicator and to summarize the outcomes in a cartographic form; to carry out the analysis of quantitative and qualitative differences in the investment climate and its constituents, including cross-border and other regions, as well as to analyze factors that influence the favourableness of the investment climate in these groups of regions.