This review explains some aspects of mucoadhesion related to the nasal drug delivery system. On the first count, the theories of the adhesion of mucoadhesive polymers to the mucosa epithelium are described. Secondly, the characteristics and application of several widely used mucoadhesive polymers in nasal drug delivery are presented. The nasal mucosa provides a potentially good route for systemic drug delivery. One of the most important features of the nasal route is that it avoids first-pass hepatic metabolism, thereby reducing metabolism. The application of mucoadhesive polymers in nasal drug delivery systems has gained to promote dosage form residence time in the nasal cavity as well as improving intimacy of contact with absorptive membranes of the biological system. The aspiration of any drug delivery system is to endow with a therapeutic amount of drug to the proper site in the body to achieve promptly & then uphold the desired drug concentration. That is why the drug delivery system should deliver drug at a state dictated by the needs of the body over a specified period of treatment. This idealized objective points to the two aspects most important to drug delivery, namely, spatial placement relates to targeting a drug to a specific organ or tissue while temporal delivery refers to the control of rate of drug delivery to the target tissue. Over the last few decades, the relevance of mucoadhesive polymers in nasal drug delivery systems has gained significance among pharmaceutical scientists as a means of promoting dosage form residence time in the nasal cavity as well as for improving intimacy of contact with absorptive membranes of the biological system. In addition, the improved paracellular absorption subsequent the swelling of the mucoadhesive polymers on the nasal membranes provides an important way for the absorption of the macromolecules through the nasal cavity. Keywords: Nasal route, Mucoadhesive polymers, Paracellular absorption,