The paper described the determination of n-alkanes in marine sediments by gas chromatography mass spectrometry with accelerated solvent extraction（ASE）for sample pretreatment.The main factors which affect the extraction yield of n-alkanes by ASE，such as proportion of extractant，temperature，static time and cycle times were discussed.The following conclusions were obtained from the study：when the long carbon chain n-alkanes need to be detected or are higher in samples，methanol-methylene chloride（1∶3,by volume）is recommended to used as the extraction solvent.Methanol-methylene chloride（1∶9,by volume）could be used as the extraction solvent while the short carbon chain n alkanes need to be detected or are higher in samples.The quantities of short and long carbon chain n-alkanes and the total n-alkanes gradually increases with increasing of the temperature，static time and number of cycles.The optimum parameters for n-alkanes extraction from marine sediments were as follows：temperature:150 ℃，static time:15 min and cycle times:3 cycles.The RSD of method ranged from 3% to 14%,except for C15 (20%).Alternatives recoveries were in the range of 84%-114%.With the advantages of practicality，reliability，easy operation，low reagent consumption and good precision，the method is suitable for the quantification of marine sediments samples with complicated matrices.