To provide a shuttle valve and shuttle valve assembly which are excellent in performances of processing, assembling and sealing and can also achieve lower pressure loss.

After arranging 1st and 2nd input ports 101, 12 and an output port 202 in the order of the 1st input port, the 2nd input port and the output port along the traveling axis of a ball 1, each of these ports is formed coaxially with the traveling axis of the ball 1. Each of the 1st and the 2nd input port is composed of an oil hole which is formed coaxially with the traveling axis of the ball 1 in 1st and 2nd individual cases 100, 10 respectively, and valve seat parts 102, 13 are provided so as to put the ball 1 in the edge part of these oil holes. A detection chamber 50 is formed to detect highest pressure by movement of ball 1 among these valve seat parts and this detection chamber communicates with the output port 202 through communication holes 14 which are provided almost in parallel with the traveling axis of the ball 1 in the 2nd case 10.