The influence of gate voltage VG on gate induced drain leakage (GIDL) current is studied in LDD nMOSFET with a gate oxide of 1.4nm and a channel length of 100nm. It is found that the split phenomena of ln(Id/(VDG-1.2))-1/(VDG-1.2) curves under different VG values occurs, which are different from the large MOSFET. Through comparing varieties of ln(Id/(VDG-1.2)) of different VG values, the mechanism of this split phenomenon is obtained. This is ascribed to the change of the hole-tunneling part of GIDL current under different VG values. The absolute value of ln(Id/(VDG-1.2)) curve slope decrease with |VG| value decreasing . It is further found that the values of slope c and intercept d of ln(Id/(VDG-1.2)) curves are linear with VG and the slopes of c and d are 3.09 and -0.77, respectively. The values of c and d quantificationally show the influence of VG on the GIDL current in an ultra-thin ultra-short MOSFET. On the basis of these results, a new GIDL current model including VG is proposed.