Fine particulate matters(PM2.5)have been associated with male reproductive toxicity,but the underlying mechanism is unclear.To explore the effect of PM2.5,32 male Sprague-Dawley(SD)rats were treated to normal saline(control group)or PM2.5 with the doses of 1.8,5.4 and 16.2 mg/kg.bw.via intratracheal instillation every 3 days for 30 days.On 30 days,the rats were sacrificed for tissue samples.In vitro,GC-2spd cells were treated to various concentrations(12.5,25,50 μg/mL)of PM2.5 for 24 h.The results showed that PM2.5 obviously decreased sperm quality,increased sperm abnormality rate and damaged testicular tissue in male rat.PM2.5 induced oxidative stress and DNA damage in testis.Furthermore,PM2.5 significantly increased the expression of BAX,cytochrome C,Caspase-9,Caspase-3 on the 30th day.In vitro,GC-2 cells treated with PM2.5 displayed mitochondria swelling and cristae breakage.PM2.5 induced S-phase cell cycle arrest and apoptosis in GC-2spd cells.Take all these results together,we hypothesis that PM2.5 might induce apoptosis via the mitochondrial apoptosis pathway through causing DNA damage and cell cycle arrest resulting from oxidative stress,and finally the quantity and quality of sperms were decreased.