© 2022. Genetika. All Rights Reserved.Suitability of ecological factors is the most important factor affecting the productivity of agricultural activities. Sensitivity of the phytochemical characteristics that are direct the product quality to the changing environmental conditions is very high. In the present study, how climate change depending on the altitude change affects phytochemical properties in plum cultivars ‘Friar’ and ‘Fortune’ fruits which were harvested at two different altitudes (200 m and 800 m a.b.s.), during two consecutive years (2017 and 2018) was investigated. In addition, under environmental and genotype modeling, genetic parameters of the properties were determined. In line with the obtained results from the study, it was determined that the phytochemical characteristics varied parallel to the altitude change within the same latitude. Generally, amount of individual phenolic compounds and organic acids were increased with altitude increase while general phytochemical characteristics such as total phenolic content and antioxidant activity were decreased. Heritabilities of general characteristics were found lower, due to high difference between genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) than organic and phenolic acids. Ranking of organic acids in both altitudes was found as malic acid> acetic acid> oxalic acid> ascorbic acid in both cultivars. In terms of phenolic acids, a stable order could not be determined while chlorogenic acid has come to the front in both cultivars. Since cultivar/location interactions found significant according to bi-plot segregation, investigating the changes at genotype level would be more accurate.