The present research was conducted in the greenhouse of the Experimental Station of Horticultural Research Station in Mansoura, Horticultural Research Institute, Agricultural Research Center during the two successive seasons of 2016 and 2017 from February 21 to June 27. One month oldgerbera plants were obtained from a commercial nursery in Mansoura, planted in 20 cm pots. This investigation aimed to improve some plant growth, flowering parameters and chemical constituents of gerbera (Gerbera jamensonii L.) plants,  by using foliar application with some amino acids (glycine, arginine, asparagine, alanine, tryptophan, and a mixture from all of them) at concentrations of 100 ppm plus the control (tap water). Application of amino acid treatments began 30 days after transplanting then repeated after 14 days intervals. The results showed that spraying gerbera plants with a mixture of amino acids at 100ppm gave the highest values of leaves and roots fresh and dry weights, total leaf area, leaf area/ plant, number of leaves/ plant, chlorophyll (A, B and total), total carbohydrates, N, P and K contents in the leaves and biggest flowers diameters (11.23 and 11.83 cm), followed by plants treated with glycine then tryptophan in the two seasons, respectively. Glycine at 100ppm recorded pronounced significant values in flowers stem length and number of flowers (7.66 and 8.00 flowers/ plant) in both seasons respectively, followed by the tryptophan treatment (7.00 and 7.33 flowers/ plant), the third highest was that of  the mixture treatment. The lowest values were obtained when plants treated with tap water (control) in both seasons, respectively.