Advanced Metering Infrastructure (AMI) combines two way communication and smart metering technologies. It can record customer’s load profiles, and thus provide system wide sensing and measuring capability to utilities. Data analytics based on AMI are emerging hotspots for utility in big data applications. Summarizing the functions of the smart meter first, this paper makes a brief description of smart meter data analytics. Then several examples of smart meter data analytics in distribution network branch impedance estimation, power flow calculation and volt/var optimization are explained in detail to show that great benefit may be available for utilities in application of smart meter data analytics.