Abstract: The principle and basic composition ofatmospheric coherenee length and isoplanaticangle measurer are presented and the results measued,at Yunnan Observatory at Phoenix Hill inKunming are reported in this article. The average values of r₀ and θ₀ are 12.4cm and 10.6 μradrespectively.The results are compared with the calculated results based on C_n² altitude distributiondata measured using ballon-borne macrothermal probe.This shows that the measured results arereliable.Finally,some factors,which could have an effect on correctness of the measurer,are ana-lysed.