Developing countries in Asia face challenges in reducing Non-revenue Water (NRW) and long-term effort is required for water supply companies. The strategies to address NRW mainly include increasing metering accuracy, pipeline rehabilitation, water use management etc., and District Meter Area (DMA) is one of efficient methods to control NRW. This paper describes methodology of designing DMA for water distribution network combined with hydraulic modelling in City A of South Asia. DMA design was implemented and the objection of the project is to reduce the present high levels of NRW. Firstly referring to as-built drawings, proposal for feeder mains was developed based on the Master Plan (target year 2040). Then according to the natural boundary, water supply situation, water quality etc., 19 DMAs were detailly designed. At last, a global model assembling all DMAs and feeder mains was done and applied to analyse the security of supply and check fire flow requirements. On the basis of the design work, construction of feeder mains and DMAs was carried out gradually, and metering facilities and valves were installed as required.