Abstract: The kinematic differentiation equations of microvibration of three coupled pendulums are obtained by using Lagrangian equations，we decouple the Lagrangian by transforming coordinates and obtain directly four conserved quantities from uncoupled Lagrangian. The Noether symmetries and Lie symmetries of four conserved quantities are studied by using inverse Noether theorem and Lie symmetry theorem.

Key words: coupled pendulums, conserved quantities, Noether symmetries, Lie symmetries