At present， the scheduled outages account for most of all the outages in the city distribution network， but the existing evaluation methods only take fault outage into account， while neglecting assessment models and methods for scheduled outage. The characteristics of the scheduled outage model and several types of construction/maintenance projects leading to scheduled outage and their impact range are analyzed first. Then， the projects are categorized into four sets based on their impact， with the mathematical model developed for each. The issue of the network structure uncertainty arising from new outlet feeders that brings difficulty to load transfer judgement is also considered in the proposed models. The planning project in Xiangzhou district of Zhuhai city is used as a real example， the results showing that the proposed scheduled outage model is effective in reliability assessment of distribution network.