OXFAm campaigners took part in a demonstration in Sheffield city centre to call for regulations to be imposed on the trading of weapons.
Gravestones were displayed at the demonstration in the Peace Gardens to represent lives lost through the illegal arms trade.
The treaty is due to be discussed by the UN in October.
Amy Roberts from Sheffield City Oxfam group said: “It was definitely a success. There were 40 of us there and people were coming over and asking what we were doing.”