Abstract：In the earliest stage of star formation, various kinematic processes compress and heat the surrounding gas intensively, driving complex chemistry, including endothermic chemical reactions, ice mantle sublimation, and sputtering. Gaseous molecular lines are now showing their power in tracing back the chemical history of several star-forming regions, which helps to disentangle the dynamic processes.

In this seminar, I will introduce two multi-wavelength line survey projects I am currently leading. The target of the first project is the shocked region generated by a low mass outflow, and the target of the second project is a sample of 70 micron dark, dense, cold regions with L/M<1Lsun/Msun and initial star-forming activities. Using IRAM-30m, NOEMA, JVLA, and ALMA, we unveiled chemical properties towards these sources, e.g., Sulfur resovior, deuteration differentiations of dense gas tracers, pc-scale CO depletion, etc. These chemical properties improve our understanding of the initial conditions and feedback of star-forming environment.