As the basic research on complexation of water soluble polymers, the complex formation of poly (methacrylic acid-acrylamide) with Cu(Ⅱ) was carried out The complex formations of Cu(Ⅱ) on the poly (methacrylic acid-acrylamide) have been investigated by viscometry, pH ti oration, and spectroscopy. The formation constants and stability constants of poly(methacrylic acid-acrylamide)-Cu(Ⅱ) were calculated from Bjerrum method. The maximum absorption of the complex system was observed at 230 nm and 300 nm In the various pH range. Thermal properties of pc]y (methacrylic-acid-acrylamide) and its Cu(Ⅱ) complex were evaluated by differential thermal analysis and thermogravimetry.