Abstract: To evaluate the effects of different doses (lactose, sucrose and trehalose) and its combining supplementation on boar spermatozoa cryopreserved in an egg yolk based extender, seven different extenders were used to freezing semen samples. The first extender, lactose egg yolk extender (LEY), was from our previous study. Sucrose and trehalose were added into the LEY diluents， completely or partly instead of lactose，to create another six extenders. Sperm qualities were assessed by motility, acrosome integrity and hypoosmotic swelling test and sperm abnormality rate response upon immediately collection, after freezing and thawing. The results showed that, as the basis of dilution of cryopreservation, LEY showed the poorest motility among the seven extenders. When sucrose and trehalose were added to the LEY diluents instead of lactose completely or partly, the quality of frozen-thawed sperm were improved. The frozen-thawed sperm motility was significantly higher(37.0%±2.6%) than the other six extenders when 33.3% lactose and 66.7% sucrose combined group (F) (P＜0.05), the acrosome integrity and hypoosmotic swelling test were higher than LEY. In conclusion， when sucrose and trehalose were added to the LEY diluents instead of lactose completely or partly, a better boar cryopreservation semen quality appeared. And the volume fraction of 33.3% lactose and 66.7% sucrose group (F) was the best.