We developed the extrusion system to evaluate the extrusion behavior such as the shear viscosity, which is one of basic properties, and the processability of mono/multilayer fain with a small amount of polymeric material. In order to measure the shear viscosity, the gear pump, the return path and the pressure sensors were introduced into the extruder with intermeshing co-rotating twin screws. The viscosity could be evaluated on-line from the volumetric flow rate of molten polymer and the pressure drop in the return path before film processing. The capacity of gear pump, the shape and size of return path were optimized to evaluate the viscosity of polymeric material, which generally undergoes shear rate of 10 similar to 1000 s(-1) in the film processing. The apparatus for mono and multilayer film processing consisted of two extruders including the multichannel feedblock and T-die with the manifold and land section. The compact feedblock was designed to receive two feedstreams, so that the product can have two layers. We investigated the on-line viscosity measurement methodology and the processability which is the neck-in phenomenon for monolayer film and the interface stability for multilayer film, using typical polymer material of 30 grams at once. The viscosity evaluated with our system corresponded with the result of commercial rheometer. It was also confirmed that the processability of mono and multilayer film could be evaluated quantitatively with our system.