This research 34.-36. is carried out as a randomized controlled experimental design in order to evaluate the effectiveness of the supplemental feeding system to improve the early feeding skills of preterm infants receiving care in the neonatal intensive care unit at the gestational week.The universe of this research will consist of preterm infants hospitalized in the neonatal intensive care of Sanlıurfa Training and Research Hospital between July 2022 and April 2023. The sample size in the study was H00: There is no difference between preterm infants with supplemental feeding system and preterm infants fed with bottle in terms of early feeding skills. According to the hypothesis G\*Power Version 3.1.9.2 (Franz Foul, Universitat Kiel, Germany) was calculated in the program. In order to determine the difference between the groups, the number of groups is 2; number of repeated measurements 3; correlation between repeated measurements 0.5; Cohen\* effect size 0.25; The statistical power was determined as a sample size of 44 preterm infants, 22 of whom were fed with supplemental feeding system and 22 of whom were fed with bottle, with 95% and type 1 error of 5%. and infants assigned to groups by randomization method. Randomization in the study determined by entering the total number of cases through the program http://www.randomizer.org. Through this program, the infants forming the sample group randomly distributed to two groups and randomization made.