In order to actualise the spatial plan passed by the local community, proper land instruments and active land politics are required by the municipality as well as the country. The local community regulates and provides expedient spatial development and a better quality of life in this area. Unfortunately, there is a lack of land instruments in Slovenia which would provide directed development of settlements and towns. What is more, land politics of local communities and the country is inactive. The objective of the thesis is to examine the expediency of taxing the planned profit which would collect part of growth of real estate value, which occurs when there is a change of use from agricultural land to residential use. With the help of good practices from abroad, I attempted to find a system which would work in my country, reduce property speculation and consistently follow the plan passed by local communities. I analysed transactions of agricultural and residential properties in 2011 in the Municipality of Ljubljana. I only took into account open market transactions. I classified these transactions into separate cadastral municipalities and took into consideration 5 cadastral municipalities with thehighest number of transactions in 2011. For each cadastral municipality, I calculated growth of real estate value when there is a change of use from agricultural land to residential use. Then I calculated the average growth of real estate value. With the help of tax level which is stipulated in the Act on Balancing Public Finances and data about the change of use of agricultural land to residential use in 2011, I calculated annual income tax revenue of the planned profit flowing into the municipal budget fund. I found out that taxing the planned profit would not fundamentally contribute to the budget fund compared to other taxes. Moreover, it is somewhat too late to tax the planned profit due to sufficient numbers of residential properties.