LPG (Liquefied Petroleum Gas) is a high potential fuel gaining popularity in domestic household and automobile sector in recent times in India. Research works in the field of flame structure and its stability are scarce. Therefore, study of its flame structure and stability characteristics is important to understand and design its burners. Since it is a multicomponent fuel, proper kinetics mechanism, at least a single step global mechanism, for simulating LPG flames should be proposed. In this paper, numerical simulations of LPG jet diffusion flames are attempted with formulated single step chemistry. Experiments are done in the lab with a burner of diameter 0.4 mm and photographs of flames are taken for different fuel jet velocity in order to study the flame heights for each fuel velocity. Numerical simulations are done by modeling LPG as a single component fluid (70% butane and 30% propane). Numerical results are compared with corresponding experimental data and are validated. The mechanism is tested for its ability to predict the flame length obtained from experiments using a criterion of LPG mass fraction. Numerical simulations are then carried out to study LPG- hydrogen jet diffusion flames. © 2018 Combustion Institute. All Rights Reserved.