Abstract: To select well immobilized carriers for ammonia-reducing bacteria and study ammonia-reducing effect of solid-state deodorant on layers' house, 7 organic carriers including wheat bran , wheat straw, wheat husk, rice straw, rice husk, corncob and sawdust were mixed with each other and formed 63 carrier combinations. A better combination from 63 carrier combinations was selected for making solid-sate ammonia-reducing deodorant. The ammonia-reducing effects of solid-state deodorant were determined through spreading deodorant onto layers' excreta in a caged layers' house with 1000 commercial layers. In this trial, the deodorant spread rate was calculated by weight loss rate of deodorant to layers' excreta, 0.5% at first period, 1% at second period, 1.5% at third period. First, second and third control periods were not spread deodorant. Temperature, relative humidity, ammonia concentration and carbon dioxide concentration were determined four times daily at 6 different positions throughout 36 days. The results show that a better ammonia-reducing effect can be obtained for the solid-state ammonia-reducing deodorant consisted of 3 kinds of powdery organic carriers, wheat husk, rice husk and corncob by absorbing 200% ammonia-reducing bacterial liquid. At first period, ammonia concentration in layers' house had insignificant change (P>0.05); At second period, ammonia concentrations significantly decreased by 15% (P<0.01); At third period, ammonia concentrations significantly decreased by 59.3% (P<0.01). But carbon dioxide concentration had insignificant decrease in all 3 periods (P>0.05). The results indicate that solid-state ammonia-reducing deodorant consisted of organic carrier compounds by absorbing ammonia-reducing bacterial liquid may obviously reduce ammonia concentrations in caged layers' house. The research can provide a theoretic reference for reducing ammonia concentrations in layers' houses.