In this study, composting of opium poppy processing solid waste with poultry manure and rough sawdust with C/N ratio of 25 (65% opium poppy processing solid waste, 14% poultry manure, and 21% sawdust, dry basis) was conducted using fifteen-identical cylindrical stainless steel reactors, each of which has an effective volume of 100 L. The moisture content of initial mixture was 66%. Five aeration rates (aeration rates executed under set point temperature, Q(min), = 0.5, 1.0, 1.5, 2.0, and 2.5 m(3)/h) were applied with fan on/off time (min) of 5/25, 7.5/25, and 10/25. The experiment lasted for 7.79 days. In the experiment, the temperature, electrical conductivity (EC), pH, moisture, organic matter, oxygen (O-2) and carbon dioxide (CO2) concentrations, total carbon and nitrogen contents were monitored. Dry matter loss, organic matter loss, carbon loss, and nitrogen loss were expressed as functions of Q(min) and on/off times. Results showed that the highest losses occurred at the aeration rate of Q(min) = 1.5 m(3)/h. Losses as functions of aeration rate with on/off time showed that the highest losses existed at the aeration rate of Q(min) = 1.5 m(3)/h with on/off time (min) of 7.5/2510.0/25.