The analysis of Shubnikov-De Haas oscillations in n- and p-type Bi2Te3 indicate the existence of a multivalley structure of valence and conduction band. In p-type Bi2Te3 the surfaces of constant energy are found to consist of 6 ellipsoids. Spin splitting of the Landau-levels was observed, the anisotropy of the g-factor in the trigonal-bisectrix plane is consistent with an existing theory. In n-type Bi2Te3 Hall-coefficient, magnetoresistance and g-factor do not follow the predicted pattern of a simple many valley model, so that the number of ellipsoids could not be determined with certainty. The presence of an additional band must be considered.