Most of the previous researches assume that each mobile client needs only one data item. However, in many situations, a mobile client might need more than one data item. In this paper, we propose an efficient scheduling method for query-set-based broadcasting, which integrates with Query Expansion Method (QEM) and the mining association rules technique. The mining association rules can globally find the data item sets (large itemsets) which are requested by clients frequently. From our simulation results, we show that, as compared to the local optimal approach in the previous methods, our Improved-QEM can construct the schedule with the smaller TQD than QEM and Modified-QEM, where TQD denotes Total Query Distance and is proportional to the average access time.