Grain boundary character distribution (GBCD) plays a vital role in determining functional and mechanical properties of polycrystalline materials. Materials which contain increased fraction of interconnected special boundaries are expected to have improved resistance to intergranular corrosion or cracking. Coincident Site Lattice (CSL) boundaries, especially E3-related boundaries are mainly responsible for improvement in properties. Present work explores the changes in nature of mechanical and annealing twins during annealing of deformed Cu-5%Zn using in-situ method. Orientation maps were collected using Orientation imaging micrography (OIM) technique during heating. Results show that twin density increases rapidly starting from the on-set of recrystallization and surprisingly not all of the twins have misorientation very close to ideal one. Change in the deviation of twins progresses and reaches to saturation with recrystallization. However there are still twins with larger deviation which are left in the material even at the state of full recrystallization. Current study elucidates the broad perspective related to mechanisms of annealing twin formation. © Copyright 2015 MS&T15®.