Utilizing Polyamide 6,6 (PA66) powders and carbon fibers (CF) to fabricate Long Carbon Fiber Thermoplastic pellets (LCFT) with two kinds of procedure and compare their mechanical properties. In order to improve the interface between PA66 and CF, an infrared heater machine add into the traditional process to produce the better LCFT pellets with good impregnation effect. There are two experiments to show the effect on the LCFT with infrared heater process, (1) comparing the characteristic of the LCFT with same weight percentage (wt%) of CF by using the process with and w/o the infrared heater machine; (2) adjusting LCFT with different wt% of CF under infrared heater process and comparing their mechanical properties. All results were measured by the mechanical specimen made from injection molding with different LCFT pellets and discussed from tensile test, bending test, Izod impact test, proportion and cross-section image of LCFT pellets by scanning electron microscope (SEM).