A field experiment was carried out in a private orchard in the province of Sulaimani - Brzenjh Township. 54 tree of European Plum Prunus domestica L. cv. Damson (local nomenclature Kadiri) were selected. The trees were 13 years old, uniform as possible in size and strength, cultivated on 3 × 4 m distance and grafted on almond rootstock, to study the effect of spraying the trees with three concentrations of urea (0, 0.5 and 1%) and potassium chloride (0, 1and 2%), and two harvesting dates at (25th August) and (7th September)) on quantitative and storability characteristics of plum fruits. Trees were sprayed early in the morning until full wetness. Urea and potassium chloride were sprayed at two time, the first was early of May, and the second was early of June, 2014. At each of harvesting dates, the fruits were divided into two groups, the first group was used for estimating the rate of fruit weight and holds the tree, and the second group placed in polyethylene bags, and stored for 6 weeks at a temperature of zero ± 1 ºC and relative humidity 85-90%, and used for determination of weight loss ratio and the internal breakdown incidence. The results showed significant decrease in the internal breakdown incidence when spraying with 0.5% urea and a significant increase in the yield of tree when spraying trees with 1% potassium chloride, As for the harvesting date, the late date (7th September) significantly reduce the rate of weight loss compared to harvesting in early date (25th August).