Abstract: The specific interaction between carbohydrate binding modules (CBMs) and substrates is of utmost importance due to it affects the biological activity of the parent enzymes and determines the chemo-mechanical properties of protein-cellulose composites. In this investigation, a quartz crystal microbalance with dissipation monitoring was employed to study, in situ and in real-time, the adsorption behaviors, conformational changes and associated thermodynamics that define the specific interactions between type A CBMs (CBM1 and CBM3) and cellulose (crystalline, CNC and nanofibrillated, CNF). CBM1 and CBM3 specifically bind to CNC and CNF substrates, with the CBM3 forming more rigid adsorbed layers at 25 °C. Despite the wide variation in adsorption enthalpy (ΔH) and entropy (ΔS), depending on the experimental conditions, a negative Gibbs free energy (ΔG) was determined from the adsorption isotherms for both CBMs. Particularly, the ΔH and ΔS associated with CBM3 adsorbing on CNF exhibited significant greater values than others due to cellulose chain disorder when swelling. The results further our understandings on the interactions between type A CBMs and cellulose substrates. Graphic abstract: [Figure not available: see fulltext.].