[Objective] To analyse seminal fluid quality of seamen with unsterility,discuss the concerned environmental influencing factors.[Method] Take 128 seamen as research group,100 drivers as control;apply the Qinghua Tongfang Auto Analytic Instrument to routinly test the seminal fluid.[Result] For the seamen with unsterility,the important indexes of spermatozoon concentration,activity rate and level-a ratio were much reduced(P