Abstract: In this paper, many factors including environmental factors (temperature, humidity, light, air current and padding) , management factors(training, feeding) and layout of a pen (proportion, shape and partition type) affecting elimination area preference and pen dirtiness of domestic pigs are discussed. To let swine eliminate in partial slatted floor, it needs reasonable pen proportion and the partial slatted floor should be put in the shorter side. Growing and fatting swine should be in separated pens avoiding overmuch area in growing stage. The higher temperature and lower air current in lying area will urge swine to eliminate in the dunging area. Otherwise, appropriate space allowance, toilet training, aeration, regular feeding, and timely disease controlling reduce the pen dirtiness to carry out cleanly raising system.