The magnetic configuration of the plasma core can be qualitatively determined by the sawtooth behavior under specific conditions due to the sawtooth characteristics may be significantly affected by localized changes of plasma parameters, particularly current and temperature profiles. The single sawtooth can be substituted by compound sawtooth when the current profile become to hollow form, i. e. two q=1 surfaces exist in the plasma core region due to modification of particular plasma condition. Because the current profile maintains the characteristic peaked shape in The magnetic configuration of the plasma core can be qualitatively determined by the sawtooth behavior under specific conditions due to the sawtooth characteristics may be significantly affected by localized changes of plasma parameters, particularly current and temperature profiles. The single sawtooth can be substituted by compound sawtooth when the current profile becomes to hollow form, ie two q = 1 surfaces exist in the plasma core region due to modification of particular plasma condition. Because the current profile maintains the characteristic peaked shape in