Abstarct: Quantum mechanics is a probabilistic theory while the classical mechanics is a deterministic one. The connection between the two, was eluding for a long time till Feynman blended them through his famous path integral representation of the kernel o2f the Schrödinger equation.The path integral formulation of quantum mechanics is a descxription of quantum theory which generalizes the action principle of classical mechanics. It replaces the classical notion of a single, unique trajectory for a system with a sum, or functional integral, over infinity of possible trajectories to compute a quantum amplitude.In this thesis, after detail discussion on Feynman path integral formulation, we will investigate different problems such as time-dependent Schrödinger equation, Dirac oscillator in the presence of Aharonov-Bohm interaction, DKP oscillator and free particle considering minimal length formalism, using Feynman path integral formulation.