To provide a light rotor assembly disk capable of meeting a rotor blade load and having a minimum inner flow diameter in a gas turbine engine.

A rotor assembly disk includes a front web 74, a rear web 76, a plurality of first stub shafts 86 ad a plurality of second stub shafts 98. The first and second stub shafts 86 and 98 have axial ends 88 and 102 and web ends 90 and 104. These stub shafts 86 and 98 are attached to the front web 74 or the rear web 76 at the web ends 90 ad 104. The number of the first stub shafts 86 is equal to that of the second stub shafts 98 and they are similarly provided at regular intervals about the axial center line 28 and connected together by fastening means 106.