Abstract: Integrating carbon nanotubes(CNTs) into micro- and nano- devices is a critical step for applying CNTs in many fields. The high contact resistance of assembled CNTs is an important factor influencing the performance of CNT-based devices. It is possible to reduce the contact resistant of CNTs by using high temperature annealing. First, CNTs were assembled by dielectrophoresis; Second, the effects of annealing temperature, annealing time, and heating rate of reducing the contact resistance of CNTs were investigated by using orthogonal experiment design and variance analysis, and the optimal parameter combination for reducing the contact resistance was obtained; Finally, the I-V characteristic before and after annealing were measured respectively. Results show that the contact resistant of CNTs can be reduced efficiently by using high temperature annealing, and the annealing temperature is the leading factor causing the reduction of the resistance. After annealing, the contact resistance can be reduced at the most by 91.59%. The I-V curves of assembled CNTs are both linear before and after annealing.