- Pool boiling is the process in which the heating surface is submerged in a large body of stagnant liquid. In the present work, heat transfer in nucleate pool boiling is modeled semi-analytically with the consideration of nucleation site density (NSD), contact angle and Prandtl number. The developed model considers variations of contact angle in bubble growing period. The suggested model is stated as a function of wall superheat, contact angle, maximum and minimum active cavities, and physical properties of fluid. According to the results, by increasing wall superheat and contact angle, heat flux and heat transfer coefficient enhance. Also, rising Prandtl number results in heat flux enhancement. Additionally, Heat transfer contribution due to latent heat and transient conduction increases with wall superheat. Natural convection contribution gradually decreases with the increase of superheat. Comparing the obtained results based on the semi-analytical models with existing experimental data and the previous models shows a good agreement.