  The thermodynamic and spectroscopic behaviour of Schwarzschild black hole
surrounded by quintessence are studied. We have derived the thermodynamic
quantities and studied their behaviour for different values of quintessence
parameter. We put the background space-time into the Kruskal-like coordinate to
find the period with respect to Elucidean time. Also assuming that the
adiabatic invariant obeys Bohr-Sommerfeld quantization rule, detailed study of
area spectrum and entropy spectrum have been done for special cases of the
quintessece state parameter. We find that the spectra are equally spaced.
