The heterocoagulation of colloids A and B was investigated by computer simulation and through experiments. In simulation, the cluster aggregation ability Å n , and cluster size n were correlated using the equation A n = A 1 n gamma; , and the three situations, γ = -0.5, 0, and 0.5 were investigated. The scaling laws of aggregation kinetics were established and the exponents were expressed as a function of the relative concentration x = [A]/([A] + [B]) of the two latices. A unique master curve represented the correlation between the temporal variations of the weight S( t) and number N( t) average sizes. On the contrary, the correlation between the exponents of the dynamic scaling laws and the relative concentration x depended on x. In the experiments, a particle counter technique was used to determine the aggregate concentration c n ( t) as a function of the aggregate size n, thereby allowing the aggregate average sizes S( t) and N ( t), which were directly compared to those obtained from simulation, to be calculated. In the heterocoagulation experiments, mixtures of polystyrene amidine latex (A) and polystyrene sulfate latex (B) of equal size, which exhibited identical electrophoretic mobility at the pH of the experiments, developed different aggregation modes. For x ⪡ 0.5, the process resembled an irreversible diffusion-limited aggregation. For x equal or close to 0.5, S( t) and N( t) increased with the features of a reversible process. Finally, for x ⪢ 0.5, the rate of the process is enhanced. Our experiments also showed that sulfate latex constituted the core of the aggregate and that the amidine latices were located around them.