According to legend, the antique second order Matsu in Wanhegong in Taichung city was a girl named Liao Pinnian who lived in Seatwen before she became a deity. This legend was accepted by the people of Nantwen and Seatwen. However, traditionally, most of Taiwan believes that Matsu is Lin Muonian. Even the first, second, and third order of Matsus are all divided by Lin Muonian. Therefore the legend of Matsu in Wanhegong is worth investigating due to its special meaning. This legend is well-known due to the individual characters of Liao Pinnian and her family. Liao Pinnian, unmarried and childless, has the same holy, pure, and virginal prototype of Matsu. Her family is referred to as Seatwen Liao's Big Fishpond Faction due to its seven fishponds. Large fishponds are also a symbol of the sea; therefore, Liao Pinnian attains the prototype character of a sea goddess. The time of this legend is in the same era when Liao's family reclaimed Seatwen. Due to their difficult life of hard toil, natural disasters, and wars, Liao's family needed a belief to support their spirits and minds; they turned to Matsu for this. Wanhegong is the closest Matsu temple to Seatwen, and there is an artery connecting the two places. Therefore, Wanhegong became Seatwen's worship center. However, given the fact that Liao families in Seatwen are not local worshippers, there still exists a gap between Matsu and them. This legend yet has enables them to establish quasi-kinship with Matsu, which increases their intimacy with her and gives them peace of mind under her blessings and protection. For Wanhegong, the legend did not change the hierarchical order of the gods, and Liao Pinnian is eligible to be an assistant of Matsu. Therefore, Wanhegong accepted this legend; and more importantly, this legend enlarged the worship community of Wanhegong to include the pilgrims from Seatwen. As such, Wanhegong has received more donations and made its reputation. Moreover, the decline of Leetoudian Street, where Wanhegong is located, was compensated with the extension of its area to Seatwen by the enlargement of the worship community of Wanhegong. Therefore, both Wanhegong and the residents living on Leetoudian Street are willing to accept the legend; this suggests that its circulation to date is certainly of a close connection with the development of these two villages.