Sambungmacan the one of the most important sites contributing information about human and cultural evolution in Indonesia, particularly in Java. There are various archaeological remains like fossils of early man and fauna, as well as their tools which where implemeted to ful fill they daily needs. Nowadays, the fossil remains are found by the society, unfortunately are not well-preserved. There is serious threat for Sambungmacan as it is located on the river bank of Bengawan Solo in which sand mining continuously takes place and conducted by local people. The existence of unwell-preserved fossils and the sand mining are considered as a part of threat for the conservation of Sambungmacan Site. Therefore, it is necessary to have an immediate action to minimize and to prevent the threat.