Great principles are simple, and looking for the essence of physics requires us to trace the roots. Binary can be arranged to combine our information world, then would the three elementary particles [1] to form the periodic table of elements? Without giving them additional attributes (such as electricity, magnetism, gravity, etc.), would they further arranged this world? This paper proved the existence of a new particle through three physical experiments. The mass of this new particle is only 10-20 of the electron, and it is named Yizi. Through the discovery of Yizi, we will reveal the cause of gravitation and expound the essence of force.