Influence of 6 different maturity degrees on soluble sugar, vitamin C, titratable acid and total soluble solids content of “smooth cayenne” pineapple was studied to ascertain the best maturity degree for eating. The results showed that the quality properties increased firstly and then decreased with the increase of maturity degree. Contents of soluble sugar and vitamin C reached the maximum of 17.76% and 178.11 mg/kg at maturity grades 7 - 8, which were remarkable significantly higher than other maturity degrees. The titratable acid and total soluble solids content reached 0.95% and 16.87% at maturity grades 5 - 6, and they didn’t change remarkably at maturity grades 7 - 8. Assessed generally, maturity grades 7 - 8 are the optimum maturity with the best flavor and nutritional quality for eating.