Abstract- According to the Republic of Indonesian’s Laws Number 11, year 2010, Cultural heritage is a cultural inheritance which differenced in the form of cultural heritage objects, cultural heritage buildings, cultural heritage structures, cultural heritage sites, and cultural heritage areas on land or in water that need to be preserved because they have important values for history, science, education, religion, and culture through the determination process. All elements or things that deserve to be embodied in the status of Cultural Heritage certainly have some criteria and limitations to be made as one of the conservation efforts made for these elements. Since the completion of development as one of the sky objects’ research at that time, the main function of the Bosscha Observatory is still running according to the initial function of the building. So that with this fact makes Bosscha Observatory has all the criteria needed by both the dynamics and the region to have the status of a Building / Heritage Area. Determination of the location of the establishment of the Bosscha Observatory was clear, where when the initial planning in the 1920s, Lembang City became a strategic location in the construction of an Observatory. But nowadays, Bosscha Observatory has obstacles, where the obstacles faced are the rapid development of settlements in the City of Lembang and cannot be avoided. This makes the main function of Bosscha Observatory disturbed by several aspects which are mainly influenced by environmental factors. With the occurrence of several environmental changes that clearly enough to interfere with the main function of the Bosscha Observatory made several parties involved in making a number of efforts in order to preserve the Bosscha Observatory as a National Cultural Heritage Building. All conservation efforts that have been carried out have a reference, namely a review of applicable laws. The purpose of this study was to find out whether preservation efforts that have been done both written and physical can maintain the main function of the Bosscha Observatory as a center for observing celestial bodies. The method used is quantitative methods, data obtained from literature studies, direct observation to the field, and interviews with Bosscha Observatory. It has concluded that some conservation efforts are still being carried out which have not been optimally carried out considering that the legal basis as a reference for all actions taken has not yet clearly defined the protection of the main functions of the Bosscha Observatory. Key Words: Preservation efforts, observation centre, cultural heritage, main function, disrupted, supporting functions