High spin states of the odd-odd nucleus 122^Ⅰ have been investigated via the fusion- evaporation reaction 116^Cd（11^B, 5n） at a beam energy of 68 MeV. The yrast band is extended up to Ⅰ^π= （29＋）. The band termination at Ⅰ^π= （22^＋） reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface （TRS） calculations. In addition, the Ⅰ^π=（29^＋） state is assigned to the [πh^11/2 （πg7/2）^2]23/2- [（vhll/2）^3 （vd5/2）^2]35/2- configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.
