In this paper, we consider the Oldroyd-B model with stress tensor diffusion in R-d with d > 2. We first establish the global well-posedness of solutions to this model for small initial data (u(0), tau(0)) is an element of (Bp-1 (d /p-1) boolean AND B-p ,1(d /p+1) ) (d)x (B( p, 1 )d/p)(d xd ) with 1