The objective of this research was to study the variation of the protein, oil, and oleic and, linoleic fatty acids content during the development and, maturation of sunflower seeds cv. ?IAC-ANHANDY? and, ?CONTISOL?. The seeding was made at October 17, 1980 and, the flowering started at 58 days after seeding for the cv. ?IAC-ANHANDY? and, at 66 days for the cv. ?CONTISOL?. Were colletted seed samples every 3 days for each cultivar in a total of 12, being evaluated the variations of protein, oil and, fatty acids (oleic and linoleic). The obtained results showed that the protein content for the cv. ?IAC-ANHANDY? had a minimum value of 13.73% at 33 days after flowering (33 d.a.f.) and, maximum of 18.23% at 54 d.a.f., and for the cv. ?CONTISOL? from 12.92% at 16 d.a.f. and, 19.42% at 37 d.a.f. In relation to the oil content, was observed for the cv. ?IAC-ANHANDY? the smallest value of 30.52% at 24 d.a.f. and, the highest of 38.30% at 33 d.a.f., whereas, for the cv. ?CONTISOL? was 7.97% at 16 d.a.f. and, 38.68% at 40 d.a.f. Relatively to the content of oleic and linoleic acids of the cv. ?IAC-ANHANDY? e respectively, the minimum values were 33.50% at 33 d.a.f. and 36.50% at 24 d.a.f. and, the maximum of 50.00% (24 d.a.f.) and 59.50% (33 d.a.f.). Considering the cv. ?CONTISOL? the smallest values respectively for the oleic and linoleic acids were 43.40% (49 d.a.f.) and, 32.06% (22 d.a.f.) occuring the maximum values of 62.97% (22 d.a.f.) and 49.87% (49 d.a.f.).