Abstract: The titania washcoats on cordierite monolith deNOX catalyst were prepared by dipping cordierite ceramic honeycomb in titania slurry using alumina sol as binder. The influence of different additives on titania coating and pH on viscosity of titania slurry was investigated. The TiO2 washcoats were characterized by microscopic analysis of ultrasonic surging, BET, SEM and XRD. It is showed that the pH of the titania slurry can affect the viscosity of slurry with the perfect viscosity at pH 1.780 of the titania slurry. Either urea or methenamine can improve the properties of titiania washcoats. The maximum loading, high adhesive capacity of the coatings and specific surface area can be obtained when 3% urea or 0.1% methenamine was added.