Cambrian carbonate rocks are widespread in the Xiadong area. One of the Cambrian standard sections of China outcrops there. In this paper the Cambrian carbonate rocks are restudied and reclassified in some new viewpoints of sedimentology and petrography. Numerous subtypes of limestone and dolostone are described. Two large transgressive to regressive cycles are recognized in the whole Cambrian: the first cycle started from the Shuijingtuo Formation and ended at the bottom of the Guanshannao Formation; the second cycle started from the upper of the Guanshannao Formation and ended at the top of the Sanyoudong Formation. Each cycle includes numerous secondary small cycles, forming the alternation of shoal facies, coastal shoal facies and tidal-flat facies. Cambrian carbonate rocks are widespread in the Xiadong area. One of the Cambrian standard sections of China outcrops there. In this paper the Cambrian carbonate rocks are restudied and reclassified in some new viewpoints of sedimentology and petrography. Numerous subtypes of limestone and dolostone are described. The second cycle started from the upper of the Guanshannao Formation and ended at the top of the Sanyoudong Formation. Each cycle includes numerous secondary small cycles, forming the alternation of shoal facies, coastal shoal facies and tidal-flat facies.