The prime object of this article is to study the perfect fluid spacetimes obeying f (R)-gravity, when B-Ricci solitons, gradient B-Ricci solitons, gradient Einstein Solitons and gradient m-quasi Einstein solitons are its metrics. At first, the existence of B-Ricci solitons and gradient Einstein Solitons are proved by two non-trivial example. We establish conditions for which the B-Ricci solitons are expanding, steady or shrinking. Besides, in the perfect fluid spacetimes obeying f (R)-gravity, when the potential vector field of B-Ricci soliton is of gradient type, we acquire a Poisson equation. Moreover, we investigate gradient B-Ricci solitons, gradient Einstein Solitons and gradient m-quasi Einstein solitons in f (R)-gravity, respectively. As a result, we establish some significant theorems about dark matter era.