The national metrology institutes always establish their time scale UTC(k) (UTC of k laboratory) based on the atomic clocks. Atomic clocks and a time scale algorithm provides an ensemble time which is better than any component clock in the system. This paper introduces establishing of Vietnam time scale UTC(VMI) (UTC of Vietnam Metrology Institute) using the comparison data of commercial ceasium atomic clocks. We applied the time scale algorithm named AT1 and an own our method and present instrument at the time and frequency laboratory – VMI. .
