Abstract: Yeniköy Melange constituting the basement in southwest Thrace, is formed by various rock blocks metamorphised in blueschist and greenschist fades conditions. The main constitues of metamorphic rocks are glaucophane-lawsoniteschist, tremolite/actinolitefels, epidote-chloriteschist and serpentinites. Morover there existmetabasite, metachert, weakly recrystallized limestone and various volcanic rock blocks. This units is in the formsof tectonic melange and its age is Upper Cretaceous. The melange has limited amount of matrix material and ismainly build up of rock blocks. Yeniköy Melange is derived from basic origin magmatic rocks, under burial metamorphism conditions, resulted from subduction ofTntra-Pontide Ocean crust under the continental crust, whichis situated between Rodop-Pontide and Sakarya continents. During the Alpine orogeny two different metamorphic phase were effected the Yeniköy Melange. Firstly, the rock undergone high pressure/low temperature(HP/LT) metamorphism with blueschist fades (Ml) conditions. At the first metamorphic stage, the glaucophaneand lawsonite minerals were derived from metabasites. However in the M2 phase, the rocks types have experienced typical greenschist fades conditions. The minerals of this metamorphic stage are, chlorite, epidote, actinolite and albite. As a result of greenschist fades metamorphism, blueschist minerals, such as glaucophane rimmed by actinolite and lawsonite were partly replaced by epidote. For the HP/LT metamorphism (Ml),we can estimate a 6 to 10 kbars pressure and 250-400 oC temperature values. Nevertheles, in M2 phase wecould estimate 4-6 kbars pressure and 350-450 oC temperatures. In this way the mineral assemblageobserved rocks and their textural features of the Yeniköy Melange may indicate a polymetamorphic evolution in the PTt path. Likewise, the greenschist fades metamorphism partly overprints the blueschist metamorphism.