The main goal of this master thesis is to display the the significance of the business planning in financing a business undertaking. Accordingly, this master thesis is going to present the importance of writing a business plan in start-up companies and their financing from the different financing resources. Furthermore, there will be demonstrated a family farm business plan for soya production. “Poljoprodukt” is a family farm which recently started with arable crops. To their purchasers they provide quality sorts of soya. The production is co-financed by aid for young farmers. Soya has seen an enormous and ongoing expansions on Slavonian fields which is the result of the size of the harvest and a reason why more and more farmers decide to grow it. The price of soya is stabile which means that the productions grows together with the needs and therefore Family farm “Poljoprodukt” has recognized a chance to start this business undertaking. The main thesis is divided in two parts. The first part contains the theoretical conception of the business plan, category and forma of the business planning. The goal of this thesis is to answer the question; why is it so important to do effort and to write the business plan and how can business plan help in growing resources? In the first part the ways of the financing a business undertaking will also be shown. In the second part of the theses is practical part, a path from a business idea to business undertaking. By business plan it is shown and analyzed cost effectiveness of business undertaken of oleaginous plant. Methods used for writing this are methods of writing expert work.