Analysis of dampness covers a variety of methods for measuring moisture content in both high level and trace amounts in solids such as building element. Analysis of dampness in heritage building is very important to avoid serious damage in heritage property. One of the heritages building in Perak is Ipoh Old Post Office Building and the other heritage building in Perak is Suluh Budiman Building at UPSI. Ipoh Old Post Office Building and Suluh Budiman Building are historical buildings which show the colonial’s features and European architecture. From the site observation, a lot of defects occurred in these buildings had been identified during the investigation and some minor defects can be seen in almost every part of the building. High moisture content or dampness at heritage wall had caused almost every part of the building experienced a very serious defect and a prompt action must be taken before the increasing of cost implication. Hence, a study on moisture before conducting any conservation and repair work is needed and it is very important to help the conservator and building environmental designer to analyze and understand the exact sources of dampness’s problem correctly and effectively. The correct analysis of dampness on heritage building will produce the best method to overcome the sources and the actual dampness problem in heritage building generally.