To understand the changes of the main nutrients and antioxidant activities of Rosa sterilis D.Shi during development. The changes of the main nutrients of Rosa sterilis D.Shi, including cellulose during development, reducing sugar, protein, ascorbic acid, total flavonoids, and total polyphenols, were investigated. The antioxidant capacity was analyzed by using the DPPH, ABTS, and FRAP. The antioxidant nutrients were determined by correlation analysis and principal component analysis. The results showed that there were differences in changes of nutrients and antioxidant activities of Rosa sterilis D.Shi during development. The content of cellulose and protein decreased with the development. The content of reducing sugar and ascorbic acid in Rosa sterilis D.Shi was consistent with the change trend of FRAP, which showed a continuous upward trend with the development. The total flavonoids content and DPPH maintained a high level in the development period. However, total polyphenols and ABTS of Rosa sterilis D.Shi increased first and then decreased with the development. Correlation analysis and principal component analysis showed that reducing sugar and ascorbic acid was the main antioxidant nutrients in Rosa sterilis D.Shi. Overall, the mature fruit of Rosa sterilis D.Shi has high nutrients and antioxidant activities.