Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?>Supported Ni-based catalyst was prepared by immersion precipitation method with Al</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?><SUB>2</SUB>O</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?><SUB>3</SUB>/MgO as carrier.Prepared catalyst was characterized by BET,environmental scanning electronic microscope,and thermogravimetry and the catalytic performance thereof in decomposing sodium hypochlorite (NaClO) to produce active chlorine was also studied.Results showed that pore size distribution of Ni-based catalyst mainly concentrated in the mesopores,which was in favor of increasing catalytic activity;suitable calcination temperature for Ni-based catalyst was <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="True" SourceValue="450" UnitName="℃">450 <SPAN lang=EN-US style="FONT-FAMILY: 宋体; mso-ascii-font-family: " Roman?; New Times Roman?? ?Times mso-hansi-font-family:><SPAN lang=EN-US>℃</SPAN></SPAN></st1:chmetcnv>;proper loading amount of Ni</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?><SUB>2</SUB>O</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: " mso-bidi-language: ZH-CN; mso-fareast-language: EN-US; mso-ansi-language: 1.0pt; mso-font-kerning: mso-fareast-font-family: 12.0pt; mso-bidi-font-size: Roman?; New Times AR-SA; 宋体?><SUB>3</SUB> was 14% (mass fraction);Ni-based catalyst prepared under the above proper conditions was applied in dealing with organic wastewater whose CODcr was 6 000 mg/L.CODcr reduced to 5 554 mg/L when with the directly use of NaClO,whereas after the addition of Ni-based catalyst in the same reaction time,CODcr declined to 600 mg/L and wastewater was basically colorless and odorless after treatment.</SPAN>