Knowledge of the dynamics of HTO in leafy plant–soil system is required to verify models, such as the NORMTRI code, which predict environmental tritium following its release. Tritium concentrations in plants has been evaluated using the code NORMTRI and experimentally by collection of samples of different plants and their soils samples. In the present study, major seasonal crop plants i.e. wheat, mustard, sugar cane, coriander, spinach, potato, were collected beyond Narora Atomic Power Station site boundary and gular, arandi, neem, ashok, amaltas, csuarina leaf samples within NAPS site boundary for analysis of HTO content. Data analysis indicated that HTO in leaf is strongly influenced by atmospheric relative humidity and type of the plant.