The objectives of this investigation were to assess the history of riverside markets in Suphanburi Province and to understand why the trade at some of the markets has collapsed. The results show that sixteen markets on the Tha Chin River in Suphanburi prospered while the river was used as the main source of transportation. Both external and internal factors caused the decline of some markets. External reasons included the emergence of road transportation, a new bridge across the river, the increase of local fairs and the construction of supermarkets. The internal factors included disregard and lack of harmony in local communities and traders leaving the area. Some markets remained and prospered. This was due to external help and community participation.