This paper analyzes the formation period of the Zhu-3 Depression in Pearl River Mouth Basin,classifies the inversion tectonic styles and investigates their influence on hydrocarbon accumulation conditions based on the seismic reflection characteristics,distribution characteristics and formation mechanism of inversed tectonics.It is proposed that two inverted tectonic phases have developed in this area.One is the faulted-inversion which develops at the end of Paleogene,and it is the superimposed tectonic which developed over faulted period to fault-depression transform period;the other is the depression-inversion which occurred during the late period of Neogene,and it is the superimposed tectonic which developed over depression period.According to the relationship between inversion tectonics and pre-existing faults and tectonics,the inversion tectonic styles of the Zhu-3 Depression of Pearl River Mouth Basin can be divided into two styles,identified as fault-limited which can also be subdivided into five fault-limited styles;and three fold-bending styles.Inversion tectonics could be served as excellent seals for oil and gas accumulation.However,since the hydrocarbon source rocks are shallowly buried during the early inversion stage,it is difficult to meet the threshold of hydrocarbon generation and adverse to the generation of oil.