It has been stated that the quality of the aromatic rice variety, Khao Dawk Mali 105 is influenced by the environment of the production area or cultivation method. In this study, 2-acetyl-1-pyrroline content of various rice samples in Thailand was investigated. The results showed that the samples from the Northeastern region, where Khao Dawk Mali 105 was cropped in rain-fed paddy fields, were higher in 2-acetyl-1-pyrroline content. The “Tungkularonghai” area, stated as being the highest quality rice production area, had the highest content among the areas in Northeastern Thailand. Samples collected from non-drought condition areas showed lower content even in the Tungkularonghai area. However, differences in seeding method did not affect 2-acetyl-1-pyrroline content in the Tungkularonghai area. These results showed that dry climate might be a factor for 2-acetyl-1-pyrroline content in Khao Dawk Mali 105. Since Khao Dawk Mali 105 is a photosensitive variety, it was expected that the ripening stage becomes uniform at a certain period which should be suitable for 2-acetyl-1-pyrroline formation in paddy fields.