Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">Experiment on determining content of ammonium perchlorate by distillation method and formaldehyde me-thod was made.Results showed the determination result made by distillation method was higher than that of by distillation method.Through comparison of experiment data,it was found that the determining difference between distillation method and formaldehyde method was at 0.35%~0.22%.It was proved that the two methods had a certain difference indeed.Factors influencing determination accuracy were put forward.It was pointed out that the trace free acids may be the cause that led to determination result at a low side.Problems should be paid attention in determination were also proposed. </SPAN>