Thiophosphoryl compounds were found to exhibit strong induction activity in the iodine-azide reaction. On this basis three procedures for their determination: titrimetric (0.15-1 mumol), coulometric (1-20 nmol) and spectrophotometric (0.5-5 nmol) have been developed. RSD in all applied methods (techniques) have been found at the 1-7% level. The induction coefficients were dependent on the type of compound applied and on the reaction condition and varied from 90 to 450.