In the RF filter, both high kt2and high Qm are required. Now AlN films are used in the BAW filters because of high Qm, but AlN has low kt2• Our group previously found the enhancement of kt2 in YbAlN films  and reported theoretical prediction of k332 in YbxAl1-xN for the range of x=0 to 11 % . In this study, we report the theoretical prediction of characteristic in YbxAl1-xN for the range of x=16.7 to 33% Furthermore, we estimate the experimental mechanical quality factor Qm of the YbAlN thin film. As a result, when Yb atomic concentration is 33%, the k332 of YbAlN is predicted to be 22%. It is approximately 3 times that of pure AlN. It was also confirmed that the Qm decreased with doping Yb.