在认识民和盆地和松辽盆地两化探工区的区域地质、构造信息及近地表地球化 学环境的基础上，探讨了顶空气指标在两工区的差异性及其原因，对比和分析了两区顶空气 指标数据特征，认为两区顶空气指标浓度数学特征的差异性是两区油气信息源、油气信道、 干扰源综合作用的结果，其中油气信道的差异性是顶空气指标数据结构特征差异性的主要影 响因素，在应用上两区顶空气的重烃（WC₂+）指标均优于甲烷（WC₁）指标。

Based on understanding the regional geology and structure，the environment of g eochemical access to earth, the paper discusses the difference and its reason in the index of head-space gas in two regions. Comparing and analyzing the data character of geochemical prospecting index, its conclusion is the difference of the consistence of head-space gas data is the integrated effects of oil reservoir, oil migrating way and interferential matter, the difference of oil migrating way is the main effect in the component of head-space gas data, the weightier composition of head-space gas apply well to two region than methane index．