Abstract: To compare the nutritional components and antioxidant capacity of red pitaya and white pitaya,the contents of crude fat,energy,tamin C,phenol,protein,total sugar and antioxidant activities were analyzed,respectively. The results showed that the significant differences in contents and antioxidant activities were found between red pitaya and white pitaya. The total sugar(18.70%±4.14%),titratable acid((0.67±0.002) g/100 g),protein((0.76±0.021) g/100 g),fat((2.28±0.04) g/100 g)and energy((2978.36±45.03) kJ/100 g)of the red pitaya were significantly higher than that of white pitaya(p<0.05),but there was no significant differences in the moisture content(p>0.05). The red pitaya was rich in flavonoid((24.9±2.3) mg/100 g),phenol((83.8±4.9) mg/100 g),vitamin C((119.5±5.8) mg/100 g)(p<0.05),and so anti-lipid peroxidation activity,free radical scavenging activity and reducing power of red pitaya were significantly higher than white pitaya(p<0.05). Therefore,the red pitaya from Guizhou were rich in nutritional components and they had high antioxidant activities,it provided to have applicable values and potential on deep processing.