Virtually all surfaces immersed in water for any period of time are colonized by microorganisms. These organisms adhere to the surface by producing extracellular polymers, predominantly polysaccharides. Biofilm formation and resulting biofouling cause serious problems for heat transfer equipment due to inhibited water flow and degradation of the heat transfer coefficient. Conventional coatings cannot be applied to heat transfer materials due to degradation of the heat transfer coefficient. Titanium, often the material of choice for heat transfer applications because of its corrosion resistance, is very prone to biofouling. Materials and/or surface modification strategies to decrease the strength of adhesion or the rate of biofilm formation would be of great value. As a first step in developing such a strategy, the interfacial chemistry between biofilm components and titanium is being investigated. This paper reports on the use of x-ray photoelectron spectroscopy to examine the interfacial chemistry between alginic acid and n-acetyl glucosamine and titanium. XPS is used to quantify the adsorbate bound to the surface under various conditions (including pH and salt content of the water), and to evaluate the adsorbate-surface bonding mechanism. Information regarding the biofilm-surface chemical interaction will be useful in developing better fouling resistant surfaces. The NSWC Carderock Division In-House Laboratory Independent Research Program supported this work.