Abstract: PRICO^® is a natural gas liquefaction technology patented by Black & Veatch, 21 sets of LNG factories using PRICO^® technology have been built in cooperation with Chemtex Company in China, 13 of which have been successfully put into operation. PRICO^® liquefaction technology is an open process which is suitable for feed gas with multiple components. The refrigerant loop is a closed adjustable system with single grade mixed refrigerant, it was proved to be mature and reliable, simple and efficient as well as easy to operate. Cold box and refrigerant compressor are core equipment of the technology, which ensure long-term stable operation. Key operations were introduced in the paper, problems encountered in field were investigated, and operation recommendations were provided, which could provide technical and operational guidance for newly built LNG factory and PRICO^® factories.