We investigated the influence of addition of cyclodextrin (CD) on the cloud point of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) aqueous solution. Both beta-CD and randomly methylated beta-cyclodextrin (RM-beta-CD) raised the cloud point of PDMAEMA solution; by contrast, the addition of alpha-CD or gamma-CD did not affect the cloud point of PDMAEMA solution. The inclusion complexation between side group of PDMAEMA and RM-beta-CD was confirmed by NMR experiments. The cloud point of PDMAEMA solution was raised gradually with the increase of concentration of RM-beta-CD. On the basis of inclusion complexation equilibrium, we deduced an equation, which clearly described the relationship between cloud point and concentration of RM-beta-CD. This analysis will provide an important theoretic guide for other related research. In comparison with copolymerization with another monomer, such a supramolecular approach avoids a series of synthesis and facilitates fine-tuning of cloud point.