INTRODUCTION. According to the calcination character of limestone, lime rotary kiln is specialized design for production of active lime. This type of kiln can work with vertical preheater and vertical cooler to achieve the advantages like high use ratio of raw materials, complete calcination, even quality, good quality lime, high capacity output, environmental and energy saving, simple ... The rotary kiln is the core equipment in a cement plant its working condition directly affects the production efficiency and clinker quality of the cement plant.To keep the rotary kiln in great working condition, we must learn how to maintain it properly during daily production. There are some notices and instructions for the maintenance of a rotary kiln.