Different effects of switching costs on customer loyalty were identified by the satisfaction and alternatives' attractiveness, when the moderating variables, the satisfaction and alternatives' attractiveness were divided into two levels: low and high.  The internet service industry was selected to find the evidences.  The results show that the switching costs would influence the customer loyalty effectively only with high satisfaction-high attractiveness of alternatives and low satisfaction-low attractiveness of alternatives contexts. In the low satisfaction-high attractiveness of alternatives context, switching costs do not has an effect on customer loyalty improving.  Only the opportunity costs influence the intention to stay with the current provider in high satisfactionlow attractiveness of alternatives context.