557300。 According to the national postal code database, the postal code of Liping County, Guizhou Province is 557300, of which the first two digits 55 represent Guizhou Province, the third digit 7 represents the postal area of Qiandongnan Miao and Dong Autonomous Prefecture, the fourth digit 3 represents Liping County, and the last two digits 00 represent the specific delivery area.