So far, the understanding of Pre-Tertiary formations in the Phu Quoc basin is eliminated due to lack of drilling and the absence of outcrops except on Phu Quoc Island and some other isles. By analogue with stratigraphic information from surrounding areas, seismic horizons may be correlated with known-age strata. Strata of pre-Cambrian and Early Paleozoic ages have not been discovered yet in SW Viet Nam but by analogue may consist of metamorphosed rocks such as chloritized phylite, sericite schist, and quartzite sandwiched with ultra basic rocks. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 19, SOÁ K1- 2016 Evaluate the geological structure, petroleum potential by interpretation the 2D seismic data of Phu Quoc basin Kieu Nguyen Binh Faculty of Technical Geology and Petroleum – Ho Chi Minh city University of Technology, VNUHCMC & PVEP Nguyen Xuan Kha Ngo Thuong San Truong Quoc Thanh Thai Ba Ngoc Nguyen Xuan Huy Tran Van Xuan Faculty of Technical Geology and Petroleum – Ho Chi Minh city University of Technology, VNUHCMC (Manuscript Received on August 10th, 2015; Manuscript Revised on October 20th, 2015) ABSTRACT So far, the understanding of Pre-Tertiary formations in the Phu Quoc basin is eliminated due to lack of drilling and the absence of outcrops except on Phu Quoc Island and some other isles. By analogue with stratigraphic information from surrounding areas, seismic horizons may be correlated with known-age strata. Strata of pre-Cambrian and Early Paleozoic ages have not been discovered yet in SW Viet Nam but by analogue may consist of metamorphosed rocks such as chloritized phylite, sericite schist, and quartzite sandwiched with ultra basic rocks. Therefore, PetroVietnam assigned PVEP to perform acquisition of 2D seismic on the area of blocks 41- 44 in order to get additional data for more precise evaluation of the petroleum potential and defining the exploration strategy in the Phu Quoc on seismic data interpretation in block 42 of Phu Quoc Basin, the Isodepth maps were constructed by approach of conversingtime to depth from isochrone maps. The results of interpretation allowed to identify many seismic closures particularly on the isodepth map of the Brown section, but these closures are located deeply above 5000m, which reliability is fair and economic effect is weak. Hence, the Brown horizon did not considered as structures identified on and concentrate to describe those determined in the Orange and Purple horizons. Result of interpretation indicated 8 closures, which could be .