Abstarct: Plum with the scientific name of Prunus domestica is one of the most important stone fruits that has a great variety in shape, color, size, taste. One of the important issues in plum cultivation is increasing yield and fruit quality. The basic nutrition of fruit trees is one of the most important things in achieving a quantitative and qualitative increase of horticultural products. It is of great importance. One of the problems of plum trees, especially the Shablon cultivar, is the formation of a small number of fruits, especially in wet areas, and the fall of the formed fruits is the next problem of this cultivar. Therefore, the purpose of this study is to increase fruit formation (Fruit set) and also to prevent harvest loss along with increasing the size and quality of fruit by feeding the trees using the elements zinc, boron, and nitrogen. To investigate the effects of foliar application of amino acid and fruit set fertilizer on the quantitative and qualitative characteristics of Shablon and Mauritania plum cultivars in Gorgan, an experimental split-factorial design was performed with 3 replications at the level of 1000 m2. The first treatment includes cultivar type in 2 levels (plum cultivar Shablon and plum Mauritanian cultivar), the second treatment includes application of fruit set fertilizer in 2 levels of consumption and non-use of fruit set fertilizer and the third treatment includes the use of amino acid in 4-time levels: 1- control ( Do not consume or zero) 2- Time of fall of sepals (small fruit) 3- Time of hardening of the core 4- Both times (small fruit and hardening of the core) were considered. The results of this study generally showed that the use of amino acids in both plum and Mauritanian plum cultivars increased the physical and chemical traits measured in this study and the use of fruit set fertilizer had similar results but in treatments with amino acid use ratio Using fruit set with amino acid, the increase of measured parameters was higher in both cultivars. The highest dry weight of fruit is related to Mauritania cultivar plum without fruit consumption with the use of amino acid in the nucleation trait stage with an average dry weight of 3.58 g which is related to stencil and Mauritania plum treatments in fruit consumption and no amino acid application with an average of 83 / Was 0 g. The highest volume of fruit was related to Plum Shabloon cultivar without the use of fruit set and amino acid consumption during nucleus hardening with an average of 41.67 ml and the lowest volume was related to plum stencil and Mauritania treatments in consumption and non-consumption of fruit set with average amino acid control treatment. It was 6 ml. Also, in terms of consumption time, in some parameters, the hardening time of the core and others, both spraying times had the highest values in the measured parameters. Plum cultivar Stencil also showed more reaction to the foliar application than Mauritania.