KLSeis is a multi-function and large-scale acquisition system with four series of and 13 correlated and independent modules. The system covers the whole process of seismic data acquisition, and its modules can function either individually or cooperatively. The windows-based and user-friendly interface along with the advanced software developing techniques makes it very easy and convenient for the user to learn and to use. The system is built on its unified architecture, unified database management, and unified graphical user interface, with the integrated system design, intelligent QC, standard operation flows, and detailed on-line help.