The present book consists of four chapters as: - The first chapter represents a general survey for different types of variable stars with more concentration on the eclipsing binaries and pulsating stars. - The second chapter deals about importance of study of eclipsing binaries and their light curves classifications, also concentrate on theories of their formation and evolution. - Chapter three through some light on the pulsation theory and deal about the mechanism of pulsation and with more details about the types of stellar oscillations with some mathematical descriptions. - The fourth chapter describe the special class of double and multiple stellar systems with variable components. We also give a short notes about some published work in this branch and speak about our future plan of work in this part.