In this paper, it is stated that environmental factors of institutional and transformational, economic and social nature have influence on the domestic trade of Ukraine and Lviv region. Aggregate turnover of domestic trade Ukraine, which shows the development of the field of trade and economic situation in the country, is chosen as a key criterion for the integrated assessment. Therefore, turnover is taken as a resulting value to identify the main factors, influencing the development of domestic trade of Ukraine. One of the stages of the integrated evaluation of the effectiveness of internal trade system transformation in Ukraine is determination of the main factors of external influence and distinguish them by subsystems. For the analysis of turnover on the national (Ukraine) and regional (Lviv) levels, an authorial division of factors is applied. The use of regression-correlation analysis and multiple regression models creation is an effective tool for reasonable selection and evaluation of factors influencing the turnover in the relevant terms of economic development of the country and its particular territories, factors management and forecasting. Construction of econometric models by using multivariate methods of correlation and regression analysis to identify factors of external influence on domestic trade of Ukraine, and in particular – Lviv region, is done in a certain sequence. It involves modeling the link between the factor and the resulting values by selecting the corresponding equation with best possible description of the studied dependency; verification of a model by statistical evaluation of reliability of the liaison indicator. Correlation and regression analysis was used to study the impact of factors on the formation of turnover in some aspects, one of which is to determine the relationship between Ukraine’s trade and the environmental factors. Factors are verified for multicollinearity, and correlation of predictors is detected basing on official statistics by using modeling. Multifactor econometric models are derived, and their quality is tested by means of multiple correlation coefficient, coefficient of determination, Fisher’s criterion and Student’s t test. The estimation results based on the models show that there is a stable correlation between turnover and the factors, included into the model. Using correlation and regression analysis we identified the highest priority factors of external influence on domestic trade, which are factors of institutional and transformation subsystem (the country’s image in the international market, trade infrastructure development, developed industrial information and communication networks, political situation in the country) and factors of economic subsystems (the country’s stage of economic development).