In the experimental colloid science literature, considerable information on the subject of polymer-surfactant interactions has accumulated over many years. However, few physicochemical studies were done on the inter-action between oppositely charged polyelectrolytes and surfactants in the early work. This may be due t o the strong interaction which starts a t a very low surfactant concentration and which is often accompanied by precipita-tion, making it difficult t o measure the low surfactant concentration in the region of interest.