Objective To investigate the effects of submarine environment on the ability of attention focusing and distribution of submariners through a comparative study. Methods To measure simple reaction time, complex reaction time, correct times of reaction, the time on targets as well as the times out of track with attention focus measuring instrument (EP701C) and attention distribution measuring instrument(EP708A). Results In the attention focusing test, the times out of track of target was significantly more in submariners with a 3-5 years service experience compared with their off-shore counterparts(t=2.03,P<0.05). The time on targets was significantly shorter in submariners with a more than 5 years service experience compared with their off-shore counterparts(t=2.27,P<0.05), and the times out of track of target was significantly more in submariners (t=2.12,P<0.05). In the attention distribution test, the correct times of reaction in submariners with 3-5 years service was significantly less than their off-shore counterparts(Z=7.03,P<0.01), and the same was also true for those with a more than 5 years service experience(Z=7.74,P<0.01). Conclusion Our findings indicate that the attention abilities of submariners are lower than those of off-shore staffs, and 3-5 year service period is the important time for impairment of attention ability among submariners.