Öz: Bu çalışma, Erzincan koşullarında bazı yerli ve yabancı kayısı çeşitlerinin dona dayanım derecelerinin belirlenmesi amacıyla; Royal, Perfection, Hungarian Best, Hasanbey, Karacabey, Rakowsky, Luizet, Silistre de Rona, Kishnewsky, Casna Drenova, Polonais, Proyma ve Paviot çeşitleri ile 2002-2004 yılları arasında yürütülmüştür. Kayısı çeşitlerinin düşük sıcaklıklara dayanıklılıklarını belirlemek amacıyla, her iki yılda da (2002-2003 ve 2003-2004) Determination of Cold Hardiness Degrees of Some Domestic and Foreign Apricot Cultivars in Erzincan Conditions (Period of 2003-2004)Abstract: This studuy was carried out to determine cold hardiness of some domestic and foreign cultivars such as Royal, Perfection, Hungarian Best, Hasanbey, Karacabey, Rakowsky, Luizet, Silistre de Rona, Kishnewsky, Casna Drenova, Polonais, Proyma and Paviot cultivars in Erzincan conditions between 2002 and 2004.The buds sampled in early dormancy (November), in middle dormancy (January) and the end of dormancy (March) for both two years were subjected to artifical freezing test (-20 o C) for different periods (0, 4, 8 and 16 hours) to determine cold hardiness of apricot cultivars. The most resistant cultivars at -20 o C were Paviot (7.69%) in the first period, Polonais (22.72%) in the second period, Royal (3.70%) in the third period for the first year whereas Hungarian Best (4.12 and 18.51%) in the first and second periods, and Luizet (2.77%) in third period. İnjurance rates of the buds subjected to freezing test showed positive correlation with electrolitic condictivity and conductivity rates whereas they demonsrated negative correlation with water content of the buds. Total sugar, starch, protein and lipid amounts of apricot culticvars increased from the beginning to the end of dormancy during freezing test periods. Viability of buds correlated significantley with total sugar (r=0.264** and r=0.416**), starch (r=-0.213*), proteins (r=0.215* and r=0.373**) and lipits (r=0.344**) contents.