The objective of this research was to evaluate the growth, physiology and quality of soursop seedlings under salt stress and different methods of application of hydrogen peroxide, as a mitigation of the deleterious effect of salinity of irrigation water during the seedling formation phase. The study, in turn, was conducted in a vegetation house belonging to the academic unit of agricultural engineering of the Federal University of Campina Grande, where it was used an Entisol of sandy loamy texture, from the municipality of Lagoa Seca, PB, during the period from April to September 2019. The treatments resulted from the combination of five levels of electrical conductivity of the irrigation water (0.6; 1.2; 1.8; 2.4 and 3.0 dS m-1) and four hydrogen peroxide application methods (M1=no application, M2=application by soaking, M3=application by foliar spraying and M4=application by soaking and spraying), in the 5 x 4 factorial arrangement, which were distributed in the entirely randomized design, with four repetitions and two plants per plot, making a total of 160 plants.