Introduction: A group of disinfectant containing NaDCC (sodium dichloroisocyanurate) is widely used cleansing agent and disinfectant for environmental sterilization to prevent various infectious zoonosis. It has been known to be safe in environment and having excellent disinfecting effects against bacteria and virus. However, in spite of its excellent effects it has been deterred in disinfectant application because of its unpleasant chlorine smell. This study was performed to develop NaDCCbased disinfectant not emitting any smell of chlorine via removal or chelation of the causative molecules but having killing effects against bacteria and virus. Materials and Methods: To produce a chlorine-based disinfectant not emitting chlorine odor NaDCC is mixed with several acid and base including sulfamic acid and sodium peroxide to chelate chlorine compound that causing smell. NaDCC disinfectant was used as a control for chlorine smell and disinfectant efficacy. The disinfectant diluted from 1: 10 to 500 to investigate chlorine smell and amount. Chlorine smell was measured by functional test and by using MINIMAX-XP-cl₂ Honeywell`s portable cl<sub>2</sub> instrument. Disinfectant efficacy was tested in accordance with the Guidance of disinfectant efficacy test for the application into veterinary area (Regulation No. 2013-34). For the disinfectant efficacy test against Salmonella typhimurium, Brucella ovis, Clostridium perfringens and AI virus the control and candidate disinfectants were diluted 3,000 ~ 12,000 times with HW (hard water containing Cacl<sub>2</sub> 0.03% and Mgcl<sub>2</sub> 6H<sub>2</sub>O 0.0139%), and 25~2,000 times with OM (organic material suspension containing 5% organic material in hard water), respectively. The valid dilution was determined the highest point showing no growth in four or more among the five replicates for tested bacteria and presenting reduction in EID50 over 4log10 for AI virus. Results: Developed disinfectants were kinds of chlorine disinfectant not emitting chlorine smell by combination with inorganic sulfamic acid or sodium peroxide from 1:10 dilution. The removal of chlorine smell of the new developed disinfectant was confirmed with functional test and an instrumental test using MINIMAX-XP-cl<sub>2</sub> Honeywell`s portable cl₂. The reason of removal of chlorine odor was the formation of stable chlorine salt by substitution of free chlorine ion with the added compounds. In comparison of the disinfectant efficacy between NaDCC and developed disinfectants against Salmonella typhimurium, Brucella ovis and Clostridium perfringens under HW condition, the highest dilution fold numbers were X12,000, X5,000 and X6,000 for NaDCC and X5,600, X1,800 and X3,000 for developed disinfectants, respectively. Under OM condition, X70, X50 and X25 for NaDCC and X70, X70 and X30 for developed disinfectants were found respectively. AI virus was completely killed at X7,000 by NaDCC and developed disinfectant, respectively under hard water condition. Under OM condition AI virus was completely inactivated with X1,000 dilution of NADCC and X1,800 dilution of the developed disinfectant. Conclusions: An improved chlorine-based disinfectant was developed, which is not emitting chlorine odor but presenting similar or superior bacterial and viral killing effects by adding chemicals that can interact and substitute free chlorine ions to form stable chloride salts. The developed disinfectant is expected to be used as a more environmentally favored cleansing and disinfectant agent.