A hot embossing method is used to fabricate Cyclo-olefin Polymer (COP) microfluidic chip in this paper. Since temperature is the most important parameter in hot embossing process

the variable temperature quasi-creep experiment is set up to study the viscoelastic character of COP for determination of the working temperature. From a point of temperature below COP’s (

T

g

) temperature

applying the embossing working pressure

the temperature-deformation curve at slow temperature rising speed(1.5 ℃/min) is obtained. According to this curve

the hot embossing of microstructure under embossing reference temperature (

T

r

) has a high accuracy and low substrate deformatiom. Experiments show that average duplication precision is 97.6% in width and 94.3% in depth. Electrophoresis and DNA separation experiments have been done on fabricated COP chip

which shows that COP chip has excellent biologic compatibility and is suitable for biochemical analysis.