Abstract: The effects of microbial fermented cassava residue feed replacing complete feed on breeding meat-duck were studied in order to provide scientific references for developing and applying products of cassava residue feed. Different proportion of fermented cassava residue feed was fed to Cherry Valley ducks during brood time(1-14 days old, duckling feed)，and fattening period (15-45days old, adult feed) in present experiment, respectively. The growth performance, economic benefits and production environment of ducks were analyzed to evaluate effects of fermented cassava residue feed. The results showed that during meat-duck brood time (1-14 days old), 1% of fermented cassava residue feed was more favorable for feed transformation of duckling than 3% and 5%. While in fattening period (15-45 days old), partial complete feed replaced with fermented cassava residue feed had no significant effects on production performance of meat-duck. Comparing the economic benefits of meat-duck breeding in different treatments, it showed that the economic benefits of treatment 4 (duckling feed compounded with 221A and 5% of fermented cassava residue feed, adult duck feed compounded with JK519 and 15% of fermented cassava residue feed) was the highest, then followed by treatment 3(duckling feed compounded with 221A and 3% of fermented cassava residue feed, adult duck feed compounded with JK519 and 12% of fermented cassava residue feed), treatment 2 (duckling feed compounded with 221A and 1% of fermented cassava residue feed, adult duck feed compounded with JK519 and 6% of fermented cassava residue feed) and treatment 1 (CK, duckling feed 221A+adult duck feed JK519). Concerning on meat-duck breeding environment, it was found that replacing complete feed with fermented cassava residue feed was more beneficial for reducing the concentration of H2S and NH3 in farm, and higher proportion of fermented cassava residue feed had more obvious effects on it. Therefore, it could be concluded that replacing complete feed with fermented cassava residue feed was conducive for improving breeding environment, reducing breeding costs, increasing survival rate and economic benefits.