Learning automata is one type of Machine Learning algorithm studied since 1970s. Compared to other learning scheme, a branch of the theory of adaptive control is devoted to learning automata surveyed by Narendra and Thathachar (1974) which were originally described explicitly as finite state automata. Learning automata select their current action based on past experiences from the environment. It will fall into the range of reinforcement learning if the environment is stochastic and Markov Decision Process (MDP) is used.