This study elucidates equilibrium and kinetic modelling for the removal of Cu(II) ion on rice straw(RS). The Adsorption isotherms are empirical relations between equilibrium uptake in solid phase and residual concentration in the liquid phase. A variety of adsorption isotherms are available in the literature which are mainly characterized as 2 and 3 three parameters adsorption isotherm models. In this study various 2 parameters adsorption isotherms are used to elucidate the equilibrium behaviour of Cu(II) removal by rice straw at an average pH = 5, by using linear and non-linear regression analysis. Similarly, Pseudo 1^st and 2^nd kinetic models are fitted on the experimental data. R², SSE, MSE, RMSE, ARE and SAE were used as the criteria of the best fit of a model in its linear or non-linear form. On the basis of R², temkin adsorption isotherm described best behaviour of the Cu(II) removal by rice straw indicating highest value of 0.9664 both for linear and non-linear regressions. Kinetic modelling showed pseudo 2^nd order kinetic model both in linear and non-linear form best represented the experimental data of Cu(II) ion removal on rice straw(RS).