By considering the master equation of the partially asymmetric diffusion process on a one-dimensional lattice, the most general boundary condition (i.e., interactions) for the multispecies reaction-diffusion processes is considered. The resulting system has various interactions including diffusion to the left and right, two-particle interactions A(alpha)A(beta)-> A(gamma)A(delta), and the extended n-particle drop-push interactions to the left and right. We obtain three distinct new models. The conditions on reaction rates to ensure the solvability of the resulting models are obtained. The two-particle conditional probabilities are calculated exactly. (C) 2005 American Institute of Physics.