This study evaluated the technical efficiency and malmquist productivity index of 25 banks in taiwan between 2005 and 2012. The paper further analysis the change of technical efficiency between two year. The empirical results show that there are 9.00% efficiency to improve on the input side. 5.6% of inefficiency is due to mismanagement, which is the major cause of bank inefficiency. During the period, the malmquist index of bank in taiwan has rise 2.46%, mainly because of technical change, which has rise 2.18%.