Odor samples from three fattening rooms with different floor systems were collected and analyzed by using triangle odor bag method under cool and warm weather. It showed that there were significantly positive correlations between odor concentration and indoor temperature and pig weight（p<0.05）. The correlation was not significant between odor concentration and relative humidity（p>0.1）. Significant differences were found in the three pig rooms with different floor systems（p<0.05）. Odor concentration was highest in the pig room with traditional concrete floor system; full-slatted floor system was the second, and the lowest for deep-litter fermentation system. The results indicated that deep-litter system was effective for odor mitigation. Odor emission factors from the deep-litter room, fully-slatted floor room, and concrete floor room were (3.39±3.33), (3.70±1.31) and (4.33±2.39)OU/ (m2·s), respectively. 