The experimental results on the timing of a copper vapor laser oscillator-amplifier system show that the timing property curve (the amplitude of amplifier output versus delay)was not symmetric, and timing properties of green beam (510.6 nm) and yellow beam x(578.2nm) were not the same. The jitter of the thyratrons was +4ns, which induced an output amplitude fluctuation of 10%-20%. The output power of the amplifier was 15% higher than that of an oscillator when the timing was correct.