The growth and structure of anionic micelles sodium dodecyl trioxyethylene sulfate (SIDES) in the presence of bivalent counterion Ca2+ were investigated by means of rheological methods and the technique of freeze-fracture transmission electron microscopy (FF-TEM). It was observed that wormlike micelles could be formed in SIDES/CaCl2 aqueous micellar solutions, according to the measurements of zero-shear viscosity eta (0), complex viscosity \ eta*\, dynamic moduli (storage modulus G ' and loss modulus G "), and the application of Cox-Merz rule and Cole-Cole plot. The structure was of character of a non-linear viscoelastic fluid and departed from the simple Maxwell model.