Abstract: The effects of milling temperature and time on the functional components and antioxidant capacity of grape seed superfine powder was studied. Results showed that milling time had highly significant influence on the granular size, tannin and total phenolic content of grape seed powder, and the milling temperature had no significant correlation with the granular size, tannin and total phenolic content. The particle size had minimum value 42.916μm when the temperature and time was-30℃ and 75 min respectively. The tannin and total phenolic contents and achieved the maximum value 0.1074g/g and 0.1415g/g at-30℃ for 45 min. The milling time had significant influence on the DPPH radical scavenging capacity, and the milling temperature had no correlation with it. The DPPH radical scavenging capacity reached the maximum value 105.715 mg at-30℃ for 45 min. The ABTS+· radical scavenging capacity had no significant correlation with milling time and temperature. The temperature had no obviously correlation with particle size, tannin and total phenolic content, and antioxidant capacity, however the experiment result showed that the lower temperature could effectively protect the polyphenols of grape seed ultrafine powder, and increased the antioxidant capacity.