The problem of mining association rules is to find the associations between items in a large database of sales transactions. Although there are a lot of previous researches on this area, a common problem occurred is that the rule only indicates if two items are related but as to in what quantities and in what combinations are missing. Without this information it is impossible to design a competitive combination of sales items since we didn't know how many units of items should be included. Therefore, if the quantities of items can be included in association rules, it will be helpful for managers to make the marketing decisions. In this paper, we introduce a new algorithm for mining association rules including the quantities of items. Then, we extend the rules so that the quantities of items can be expressed as user-defined intervals or fuzzy terms.