The investigation was carried out on three apple cultivars (Idared, Golden Delicious & Jonathan) to study the rates of photosynthesis and respiration and pigments content during fruit growing and maturation processes. During fruit growth and maturation, there is a decrease in the photosynthesis of all studied cultivars. Apple, included in the category of climacteric fruits, presents the following characteristics of the respiration: during June – August the intensity of the process decrease, but during maturation stage it increase. The maturation process of the fruits is characterized by changes of pigments content, which lead to the realization of the characteristic treats of color. This study shows a negative correlation between fruit diameter and photosynthesis rate, respiration rate, fruit chlorophyll a or b, fruit content and a positive correlation between diameter and fruit carotenoid fruit content.