Relationship between pyrrolic nitrogen compounds in oils from Lunnan Oilfield of Tarim basin, Xingzhang and Chaoyanggou-Changchunling Oilfields in Songliao basin and oil maturity has been discussed. The results indicate that the concentration of various pyrrolic nitrogen compounds in the oils increases with the increasing matunty, together with the different rate of isomers having structural difference. Within the maturity range of oils analyzed, the increasing rate of isomers with nitrogen-shield is higher than ones with nitrogen-exposed. It is suggested that the trend of pyrrrolic nitrogen compounds varying with maturity probably exists in oils once the compounds originally generated, which is determined by degradation mechanism of kerogen other than isomerization of isomers in oil during thermal evolutiln. The significance lf the Study lies in that contributiln of thermal maturity to the concentration and relative distribution of pyrrrolic nitrogen compounds should be considered when the compounds are used as migration indicators Relationship between pyrrolic nitrogen compounds in oils from Lunnan Oilfield of Tarim basin, Xingzhang and Chaoyanggou-Changchunling Oilfields in Songliao basin and oil maturity has been discussed. The results indicate that the concentration of various pyrrolic nitrogen compounds in the oils increases with the increasing matunty,同以 用 the different rate of isomers having structural difference. Within the maturity range of oils analyzed, the increasing rate of isomers with nitrogen-shield is higher than ones with nitrogen-exposed. It is suggested that the trend of pyrrrolic nitrogen compounds varying with maturity probably exists in oils once the compounds originally generated, which is determined by degradation mechanism of kerogen other than isomerization of isomers in oil during thermal evolutiln. The significance lf the Study lies in that contributiln of thermal maturity to the concentration and relative distribution of pyrrrolic nitrogen compounds should be considered whe n the compounds are used as migration indicators