The (3S,3aS,4S,4aS,7S,9aR,9bR,12S)-7,12-dihydroxy-3-methyl-6-methylene-2-oxoperhydro-4a,7-methano-9b,3-propenoazuleno[1,2-b]furan-4-carboxylic acid (Gibberellic acid (GA)) extraction from aqueous solution by Amber lite La-2 in different diluents (isoamyl alcohol, or octan-1-ol, or decan- 1 -ol) was studied. According to experimental results, some thermodynamic parameters such as distribution coefficients (K-D), loading factors (Z), and extraction efficiency (E) were calculated. The best extraction efficiency, distribution coefficient, and loading factor were determined by isoamyl alcohol diluent at values of 98 %, 97, and 4.6, respectively. Besides, the linear solvation energy relationship (LSER) model regressed to experimental results with a regression coefficient (R square) of 0.98. The LSER model predicts results close to experimental data.