The formation of tetra-PEG gels, a model network with a well-defined structure, was investigated using particle-tracking microrheology. The dynamic scaling and critical relaxation exponents in the sol-gel transition were determined by applying the time-cure superposition method. Some values of the exponents differed from those of the Rouse model theory. This was attributed to the failure of the theoretical assumption that the cluster structure formation follows the percolation model theory on a three-dimensional lattice.