Abstract: With the liberalization of electricity sales side, residents have more independent choices for electricity retailers. Retailers need to design electricity plans suitable for residents based on actual electricity demand. Therefore, a residential electricity package considering the user utility in off-peak and peak seasons is designed. Firstly, a user utility function based on average monthly household electricity consumption is calculated, and the probability of various electricity package chosen by users is obtained.Secondly, with the objective of maximizing the retailers’ profit, a cost-benefit model of the packages is established. Finally, the model is solved by the particle swarm algorithm. The case simulation results show that the setting of retail packages provides users with more choices; not only the electricity utility of users is improved, but also the expected profit of retailers is effectively increased; at the same time the peak-valley load difference of residential electricity is reduced.