Customized bus (CB) route planning and adjustment have an important impact on passenger occupancy rate and passenger’s continuous choice behavior. Based on the stated preference survey on the continuous willingness to use of monthly-ticket CB users from 31 customized bus routes in Dalian, a binomial Logit model is constructed on the basis of random utility maximization theory. The result indicates that discount and detour distance are the two most significant influence factors of continuous willingness to use. The longer the travel distances are, the higher the willingness to continue using CB. The distance boundary with operational advantage between CB and conventional public transportation is 8 km in Dalian. For every additional 1.6 km of detour distance, a 10% fare reduction is required to maintain existing customized bus users, while at least 10% new subscribers should be induced to improve operation profit.