In this paper, we study certain multilinear operators of fractional integral type defined by \[ I^{\vec{A}}_{\alpha}\vec{f}(x)=\int_{% %TCIMACRO{\U{211d} }% %BeginExpansion (\mathbb{R} %EndExpansion ^{n})^m}\frac{f_1(y_1)\cdots f_m(y_m)}{|(x-y_1,\cdots,x-y_m)|^{mn-\alpha+\sum\limits_{i=1}^m(N_i-1)}}\prod\limits_{i=1}^mR_{N_i}(A_i;x,y_i)d\vec{y}, \] where $0< \alpha