The Standard Model is very successful in the particle physics, but remains several mysteries, such as the origin of the gauge groups, Higgs mass, and the fermion mass hierarchies. They are resolved by the Beyond Standard Models (BSMs), and the BSMs could be tested at future experiments. In this talk, I especially introduce the SO(10)-GUT model, which is one of the promising BSMs, and discuss the flavor physics relevant to the GUT model. If I have time, I also introduce my recent work about flavor symmetric models and their flavor physics.