The study compared two telephone-sampling methods,one is thetypical directory-based systematic sampling with random number replacementof the last digit,and another is random digit dialing(RDD)using PPS method.Results showed that the RDD methodperformed well with its advantage on perfect coverage.The cost oflower contact rate due to broader coverage is not high,and there isno difference between the two methods in terms of sample's geographicalrepresentation.