Walker circulation represents one of the components of tropical circulation which are tightly coupled with each other, producing strong convection centre around the Western equatorial Pacific. The Walker circulation cell describes the zonal-vertical circulation with air rising above equatorial Western Pacific, westerly winds in the upper troposphere above Pacific, sinking air above equatorial Eastern Pacific and easterly winds in the lower troposphere in direction towards Western Pacific. In this master's thesis possible indicators of Walker circulation variability will be presented in terms of velocity potential and inertial-gravity components of flow. The trend analysis of the intensity of Walker circulation will be described assuming the trend as a consequence of differential forcing above Indian ocean and Southeastern Asia in the last century. Changes in Kelvin wave will be studied, due to Kelvin wave being the most significant wave in the tropics.