||In the economic research market transparency is the knowledge about goods, their prices and their allocation. Competitive market transparency requires a competitive market. Unfortunately, caused by heterogeneous and immovable real estate the land and real estate market isn’t a competitive market. Nevertheless, improvement of market transparency is a major goal of market research. The land and real estate market is divided spatially and factually. This paper will present empirical and theoretical efforts to improve transparency of the land and real estate market. It presents the preliminary results of a research project started in 2007. While the final report of the research project deals with empirical aspects, the doctoral thesis deals with a theoretical model to improve market transparency. Requirements to improve transparency of the land and real estate market can be derived by an em-pirical study of current situation. Therefore, four issues have been analyzed. To begin with, market information that is currently published on a national level has been analyzed. Market information could be grouped by publisher and characterized by content: Different publishers focus on different aspects. For the second place, published information from different countries has been compared internationally. Different countries have different legal and economic frameworks. To fit require-ments of users both frameworks should be considered within a comparison of market information and market transparency. For the third place, market participants have been asked for their demand for market information. For the fourth place, scientific and practical papers point out aspects of mar-ket transparency or demand for market information of market participants. All issues were combined to a system to improve nowadays markets transparency. The idea of the empirical study is to identify very important factors (key factor) to describe the land and real estate market. Another effort is deriving key factors theoretically. It can be done by comparing different suggestions written in literature or by modeling the demand for market information used in different services. However, different services like valuation, market and location analyses or forecasting - each sup-porting transparency – require different parameters. These services can be formed to a model of market transparency. This model allows considering all aspects of market transparency. The parame-ters of different services are combined in the doctoral thesis. The weights of different parameters are estimated by using Multi-Criteria Decision Making. Due to quantitative parameter the decisional problem is fuzzy. The doctoral thesis will handle these problems by using methods like PROMETHEE, ELECTRE and AHP. Various benefits of these methods are going to be connected. The theoretical model results a set of key factors. The key factors derived in the empirical study are going to be tested practically. The results of the doctoral thesis are going to be compared with the results of the empirical study and the statements of market participants derived in the survey. Although the research is located in Germany, ideas and results could be transferred into other countries.