In a turbine rotor blade assembly 1 of the present invention, each turbine rotor blade 10 includes a platform 11 having a blade root 12 fixed to a turbine disk 30, a profile 13 rising from the platform 11, and a shroud 14 provided at a top end of the profile 13. The shroud 14 of the present invention includes a first contact end part 15 that comes into contact with an adjacent shroud adjacent to one end side in a circumferential direction, a second contact end part 16 that comes into contact with an another adjacent shroud adjacent to the other end side in the circumferential direction, and a main body part disposed between the first and second contact end parts 15 and 16. One or both of the first and second contact end parts 15 and 16 are lower in rigidity than the main body part.