Buying a house is considered to be an increasing necessary demand. However, choosing the right one is a complex and time-costing decision. In this research, a method for knowledge representation of an expert system in real-estate investment is proposed. This method organizes the knowledge base of the system based on combining market surveying data in real-estate for each category of customers. Through that, a content-based searching system using the personal demographics, as an expert system, is proposed. This system supports both customer and real estate agent to find the suitable house fitting their desire and budget. This system is designed to extract information of the customer information to enhance the conventional searching method which only treat house property as the only input.