Interfacial flows include lots of problems in fluid mechanics such as, Oil industry, design of Boilers and reactors. Regarding to importance of these kinds of flows, two well-known eulerian methods named “Volume of Fluid” and “Level Set” are compared with each other completely. In order to judge against these two methods, motionless droplet and rising bubble are numerically modeled with the assistant of these two methods and the results are verified with available experimental data. By comparing these two methods, we came to this conclusion that Level set method can calculate the curvature of the interface with great accuracy. On the other hand Level set method can not satisfy the mass conservation with great accuracy. Volume of Fluid method is based on volume conservation in each fluid, therefore the mass is preserved in each phase of incompressible flows with great accuracy. On the other hand, as a result of using discrete function for modeling the interface, curvature can not be calculated with fine precision. Because of the accuracy in calculating the curvature of the interface and acceptable mass conservation in the time steps that we need for modeling our problems, Level set is used for modeling Problems such as falling droplet, rising bubble, coalescence of two Bubble and also droplet impact on a solid surface. At first falling droplet is studied for different Weber numbers, and values for Weber number is found which for them bifurcation of the droplet occur. After that rising of three dimensional axisymmetric bubbles is studied. The reasons for the deformation of the bubbles are discussed theoretically. Comparing the numerical results with available experimental data reveals the accuracy of the method. In addition the coalescence of two bubbles which is complicated phenomena in multiphase flows is numerically modeled and the results are verified by experimental data. At last by adding contact angle model to the level set code, changing the frequency of applying reinitialization equation and increasing the number of fictitious time in reinitialization equation, droplet impact on solid surface is modeled numerically. Steps of droplet impact such as advancing and recoiling are numerically captured. The main advantage of our simulation compare with previous ones is that the Level set function is not change near the contact point of solid, liquid and gas. Finally the recoiling velocity is calculated for different initial velocities and theoretical discussion is done for the reasons of these different recoiling velocities. Key Words- Two phase flows, Surface tension, Level set, VOF