Abstract: In order to investigate the effects of added holes on vibration of a structure,a stiffened cylinder was studied via finite element method.The mean-square velocity level of the structure was calculated with different radiuses,positions,amount of holes,and different bulkhead with holes,yet the stiffened structure near the hole was ignored.And the frequency response curve of mean-square velocity level was obtained under different conditions.The results show that in 150～350 Hz the effect on mean-square vibration velocity level is limited under four conditions,but within the band 350～1 000 Hz,the effect on mean-square velocity level becomes greater at some exciting frequencies.Holes can both satisfy the engineering requirements and decrease the mass of the submarine,but the changes of structural vibration performance should be further investigated.