The Rare Isotope Accelerator complex for ON-line experiments (RAON) is a heavy-ion accelerator experiment facility under construction in Korea. This facility aims at a beam energy of 200 MeV/u and a maximum beam power of 400 kW and is expected to be completed by 2021. A large-scaled experiment facility like RAON requires a timing system for precise-synchronized operation. For this purpose, domestic accelerator facilities mainly use timing systems that are foreign products. The accelerator engineering team of RAON has successfully developed the RAON timing system in cooperation with a domestic company. The signals from the RAON timing system synchronized with an radio frequency (RF) reference clock and a global positioning system (GPS) are distributed throughout the RAON site via the dedicated timing network (3.25 Gbps). The time accuracy of the timing system is 12.3 ns synchronized with the RF reference clock (81.25 MHz). All signals (triggers, pulse delayed clock, and external signals) of the timing system developed using the Experimental Physics and Industrial Control System (EPICS) software module are configurable on a software. In addition, the RAON timing system supports the more flexible system for the various beam operation mode and improves the performance of the control system. This paper describes the results of the design and development of the RAON specific timing system.