Abstract: A study was carried out with the aim to evaluate the effect of different physical factors viz., temperature, light and relative humidity on the pine seedlings growth and ectomycorrhizal development. Moderate and high light intensities favoured mycorrhizal colonization and seedling growth. Pine seedlings inoculated with Pisolithus tinctorius compared to other fungi attained maximum growth. Survival of pine seedlings was higher under moderate light intensity than low and high light intensity. Seedling growth and mycorrhizal colonization was better at 25 ° C than 10°C. Variation in humidity did not show much difference in mycorrhizal colonization and seedling growth. However, seedling survival was greater at high than at low humidity. Pine seedlings showed best survival with ½ P level (46.153 mg Phosphorus kg-1 soil) of phosphorus at 25°C temperature and under moderate light intensity. Among the mycorrhizal fungi used P. tinctorius was the most effective endophyte and was followed by Laccarai laccata, Rhizopogon luteolus and Collybia radicata under various physical factors. On the basis of performance shown by P. tinctorius, L. laccata and R. luteolus, it may be stated that these fungi can be utilized for inoculation with pine seedlings in nursery under aforestation programme.