The　effect　of　various　metal　chlorides,　namely　FeCl3,　AlCl3,　CuCl2,　and　ZnCl2,　on　the　thermal　decomposition　of　nitrocellulose　(NC)　was　studied　using　a　synchronous　thermal　analyzer　(STA).　An　aqueous　solution　of　10　mass%　metal　chlorides　was　added　to　NC　and　was　then　compared　with　pure　NC.　The　results　revealed　that　FeCl3　and　AlCl3　promoted　notable　NC　decomposition,　but　CuCl2　and　ZnCl2　inhibited　decomposition.　Therefore,　the　addition　of　trivalent　metal　chlorides　can　increase　the　explosion　risk　in　NC.　By　contrast,　divalent　metal　chlorides　can　function　as　inhibitors.　In　addition,　the　kinetics　of　NC　and　NC　mixed　with　metal　chloride　were　determined.　The　addition　of　metal　chlorides　promoted　or　inhibited　NC　decomposition　but　did　not　change　its　reaction　mechanism.　This　study　provides　crucial　information　for　improving　the　safety　of　NC　storage,　transportation,　and　use.　©　2021　The　Authors