To reconstruct the current density profile in tokamak plasmas, an inverse analysis method is under development. In the analysis, the boundary integral equation for a polynomial expanded current is coupled with several constraints. Recently, (i) the method of transformation from measured poloidal field values inside the plasma to current density has been improved. (ii) The "generalized cross validation" has been introduced to estimate the optimized value of the Tikhonov regularization parameter. (iii) A new method to apply the equilibrium condition has been added to the analysis. Due to these improvements, the reconstructed results are quite accurate for parabolic plasma, roughly agree with the reference values for other types of plasmas.
