Scalar finite-element method is used to analyze ion-exchanged channel waveguides. First, the accuracy of the calculation is tested by comparing the theoretical prediction and experimental measurement of cut-off wavelengths. Excellent agreement is observed. Then, this method is utilized to study the mode profile of ion-exchanged channel waveguides with a SiO2:TiO2 cover layer. It is shown that waveguides with circular mode profile can be achieved. Finally, the ion-exchanged waveguides with a grating are studied. the effect of grating parameters on waveguide behavior is investigated.