In order to improve long term stability of a-Si:H TFT for AM-OLED application a new driving method compensating Vth shift requires a new device structure of which hole injection is enhanced. ITO film was investigated for the hole injection material because it is essential material for display devices and has high work function favorable for hole injection. From I-V characteristics of TFTs with two types of source and drain material, i.e. Cr and ITO, the contact properties were measured and compared. Although electron injection property of ITO was worse than Cr, hole injection property was comparable to that of Cr.