  An analysis of precession fishbone, diamagnetic fishbone and internal kink
mode in Tokamak plasmas is presented via solving the fishbone dispersion
relation. Applying the dispersion relation to a typical EAST discharge,
excitation of precession fishbone due to Neutral Beam Injection is successfully
explained. The real frequency and growth rate of diamagnetic fishbone and
internal kink mode are calculated, and the relevance of the diamagnetic branch
is also discussed for the possible equilibrium profile.
