Abstract: According to the spin in Gibbons-Maeda dilaton, having applied WKB approximation, the r-number wave （pkr） is obtained through the equation of neutrino fields spinned 1/2. Basing on it, using brick -wall method to calculating the free energy and the entropy of neutrino fields that near black hole, and having compared with the entropy of scalar fields, the main entropy of neutrino fields is found 7/8 times as much as the main entropy of scalar fields.

Key words: G-M dilaton, neutrino, entropy, brick-wall model