In this study, two very important surface parameters, such as the effects of surface roughness and wettability were investigated by creating a hydrophilic and hydrophobic nano-coatings and also combined surfaces in the pool boiling process. In these experiments, boiling of silica nanofluids with two different base fluids on a circular flat plate heater (30 mm in diameter) were carried out for evaluating variation of the characteristics of nanofluid boiling, including critical heat flux (CHF) and heat transfer coefficient (HTC) due to modification of surface roughness and wettability. Experiments were carried out with three different concentrations of 0.006, 0.008 and 0.01 vol.% for boiling of nanofluid with hydrophilic and hydrophobic nanoparticles, and also in an optimum concentration (0.008 vol.%) for the combined states of two nanofluids, until reaching the CHF. It was observed that during the boiling process, coatings with different roughness of hydrophilic and hydrophobic nanoparticles were created due to deposition of nanoparticles on the heater surface, which the average roughness was directly related to the concentration of nanofluid boiling. After creating nano-coating surfaces, DI water boiling was performed on these modified surfaces and compared with DI water boiling on the polished surface. Results showed that CHF increases with the concentration of hydrophilic nanofluid, while this parameter decreases for hydrophobic nanofluid. In the experiments of combined surfaces, the most improvement of CHF compared with CHF of DI water on the polished surface was for combined surface 3 (97% increment),