This text contains a series of subjects such as stellar structure and evolution, stellar oscillation and stellar atmosphere. It is divided into four parts. Part one gives a solid theoretical foundation of stellar astrophysics, which includes radiation theory, stellar convection, nuclear energy generation, opacity and equation of state of stellar matter. The second part deals with the structure and evolution of single and binary stars of various masses. Effort is taken to explain physically the phenomena occurring in various stages in the star's life. Part three presents the theory of stellar oscillations based on radiation hydrodynamics. The final part deals with the theory of stellar atmosphere, including LTE and non-LTE model atmosphere, line formation and radiative transfer in moving atmosphere. A feature of the book is the inclusion of a set of numerical modelling for stellar structure and evolution, stellar pulsation, LTE and non-LTE model atmosphere and line formation.