Tun Sakaran Marine Park, TSMP, is home to endangered species of giant clams. However, there are few studies regarding the species-specific abundance of giant clams in the park. Thus, a preliminary survey was conducted from 17th to 23rd February 2014 to assess the abundance of giant clams (Tridacna squamosa, T. crocea, T. maxima, and Hippopus hippopus). Transect lines of 100m were laid with the same depth contours of the reef (shallow reef 2 – 6m depth), and giant clams found within the study area were identified and recorded. The results showed that the average abundance of giant clams is 7.17 individual/100m2 . T. crocea has the highest abundance (6.98 individual/100m2), followed by T. maxima (0.15 individual/100m2), T. squamosa (0.02 individual/100m2) and Hippopus hippopus (0.02 individual/100m2). Reefs of Sibuan, Mantabuan and Lagoon of Bodgaya-Bohey Dulang are believed to be an important habitat for T. crocea as most of these species were found there. However, further research covering deep reefs and intertidal areas over larger areas are required for generating comprehensive information.