Polyester fibers and fabrics have been dyed with disperse dyes in alkaline dyebath such as alkaline buffer and alkaline auxiliary(JPH-95) comparing a traditional acidic dyeing. After dyeing the samples were extracted with 100% DMF, and washing and rubbing fastnesses were measured. In dyeing at $100^circ{C}$ the dyeing rate increased with decreasing fiber denier, regardless of dye baths, whereas the dyeing rates of the same denier fiber increased in the order of alkaline dyeing>acidic dyeing>JPH-95 dyeing. In dyeing at $130^circ{C}$ the dyeing rate of PET fiber in JPH-95 dye bath decreased compared with the other two types of dye baths. In the time and temperature curve the dye uptake of JPH-95 dyeing was higher than the other two types of dye baths in the range of low temperature$(95~115^circ{C})$. The equilibrium dye uptake increased in the order of 0.52d>2.04d>0.05d fiber. Washing fastness had no change in all three types of dye baths. But rubbing fastness was not good for alkaline dyeing except black dyes.