Parallel computing of the transient radiative transfer process in participating media is studied with an integral equation model. Two numerical quadratures are used: the discrete rectangular volume (DRV) method and YIX method. The parallel versions of both methods are developed for one-dimensional and three-dimensional geometries, respectively. Both quadratures achieve good speedup in parallel performance. Because the integral equation model uses very small amount of memory, the parallel computing can take advantage of having each processor store the full spatial domain information without using the typical domain decomposition parallelism, which will be necessary in other solution methods, for example, discrete ordinates and finite volume methods, for large-scale simulations. The parallel computation is conducted by assigning a different portion of the quadrature to different compute node. In DRV method a variation of the spatial domain decomposition is used. In the case of YIX scheme, the angular quadrature is divided up according to the number of compute nodes. These parallel schemes minimize the communications overhead