  The relation between the quasinormal modes (QNMs) and the second order
thermodynamic phase transition (SOTPT) for the Reissner-Nordstr\"om (RN) black
hole is studied. It is shown that the quasinormal frequencies of the RN black
hole start to get a spiral-like shape in the complex $\omega$ plane and both
the real and imaginary parts become the oscillatory functions of the charge if
the real part of the quasinormal frequencies arrives at its maximum at the
second order phase transition point of Davies for given overtone number and
angular quantum number. That is to say, we can find out the SOTPT point from
the QNMs of the RN black hole. The fact shows that the quasinormal frequencies
carry the thermodynamical information of the RN black hole.
