在理论和数值模拟上，已经预测HII区与周围分子云相互作用有可能触发恒星形成。近来单个样本或者较小样本对电离氢区的观测研究，发现了不少触发恒星形成的证据，但是这个观点仍备受争议。另外，所有真实的天体都是三维结构，而多数观测的结果展示了电离氢区周围介质是二维环状结构，所以电离氢区周围介质的结构和物理性质仍需要深入研究。本项目将结合国内青海德令哈的13.7米毫米波望远镜和KOSMA毫米/亚毫米波望远镜，以CO、HCO+及其同位素分子的不同跃迁谱线数据为基础，对76个壳状或部分壳状的HII区进行研究和分析。由于我们使用CO和HCO＋多条谱线对HII区周围的介质进行观测，同时结合其它释放的红外波段数据，所以我们可以对HII区触发恒星形成提供约束和新的证据，以及可以相对准确的确定分子云的动力学温度和密度。通过大样本的统计分析，本项目也可以增进对HII区周围介质的动力学结构和物理性质的认识。

In the theoretics and numerical simulation, it has predicted that HII regions interacted with the surrounding molecular cloud are likely to trigger the star formation.Recently,a single sample or small samples of observational studies for HII regions, has found a lot of triggered star formation evidence,but this view is still controversial. In addition, all real objects are three-dimensional structure, however,the majority of observations show that the surrounding medium of HII regions is two-dimensional structure of the annulus , so the structure and physical properties of the medium surrounding HII region still needs to be studied further.The project combined the Qinghai Delingha 13.7 meters telescope and KOSMA millimeter/submillimeter telescope, CO、HCO+，and their isotopic molecules of different spectral line data as the foundation, conducts the research and the analysis to the 76 HII regions of shell-like or partial shell-like. Since we use CO and HCO+ multiple spectral line to observer the medium of the surrounding HII region, combined with the release of the infrared observation data, can provide constraints and new evidence on star formation triggered by HII region. Through the statistical analysis of large samples, this project can also promote the understanding for the dynamics structure and physical properties of the surrounding medium of HII region.