In this paper, we study
formal deformations of Poisson structures, especially for two families of Poisson
varieties in dimensions two and three. For these families of Poisson structures, using
an explicit basis of the second Poisson cohomology space, we solve the deformation
equations at each step and obtain a large family of formal deformations for each
Poisson structure that we consider. With the help of an explicit formula, we show
that this family contains, modulo equivalence, all possible formal deformations. We
show moreover that, when the Poisson structure is generic, all members of the family
are nonequivalent.