A considerable amount of public funding in the form of VC has been made available in Europe, especially in its least developed parts, to decrease market gap for such funding. Still, even after many public interventions, the market's deficiencies in many countries are not eliminated, and the industry still stands on public support. There are many studies regarding factors influencing the VC supply side and as a result ability of a particular country to have a self-sufficient VC market. The study aimed to build a comprehensive list of determinants of VC supply and identify most triggering in unmatured VC markets. The paper presents the VC supply determinants’ conceptual model. The model was built on the results of the literature content analysis. As per the model, the local market and legal environment is the most crucial determinant of the country's VC supply. The public support and the features of local society has impact on the supply, but much less than the environment and not direct but through interconnectedness with other determinants. The validation of the conceptual model by analysing data from mature and immature VC countries confirms the validity of the proposed model. As suggested by the model, the total supply in the countries with a beneficial market and legal environment has little correlation directly from other determinants. In the undeveloped VC countries, the market and legal environment also is the main determinant of the supply. As the environment has huge flaws there, the organic supply in these countries is very low. The public support has a stronger impact in these countries, still not sufficient in a longer period without interconnectedness with other factors substantially improve the VC supply. Applying VC determinants’ model logic it is understandable that improvement of the supply is long-term step-by-step process, which could be reached continuously providing public support and directly and indirectly improving the market and legal environment and society’s acceptability and fitness for VC.