This study used a 2*3*2 between-subjects experimental design to examine the effect of on-line shopping referent price and promotion situation on consumer's purchasing intention. And it also examined the moderating effect of advertising spokesperson (celebrity/non-celebrity). This study found out that reference price (high or low) was significant difference on consumer's purchasing intention. Promotion situations (time limited, amount limited, or time limited and amount limited) was significant difference on consumer's purchasing intention, either. Moreover, this study found out that in reference price (high or low) or promotion situation (time limited, amount limited, or time limited and amount limited), advertisement spokesperson had a moderating effect on consumer’s purchasing intention.