A fixer for handheld, portable, mobile devices includes an extension rod that has one end provided with a positioning frame for holding and positioning an external mobile device, and has an opposite end provided with a securing member for attaching and securing the extension rod and the positioning frame onto an external article, wherein the securing member and the external article are fixedly connected by a locking unit so as to suspend the mobile device. The fixer is portable and can be easily and quickly mounted on or dismounted from any nearby handrail, particularly as one typically provided in a public transportation vehicle.