The purpose of this study was to investigate market mechanism of Para rubber in the Northeast of Thailand, including Nong Khai, Udon Thani, Khon Kaen and Buriram provinces. Data were collected by means of interviews with Para rubber farmers from 320 households, including 38 households in Nong Khai Province, 106 households in Udon Thani Province, 121 households in Khon Kaen Province, and 55 households in Buriram Province. It was found that most of the rubber farmers were in the age range of 41-50 years, completed the primary school (Grade 4 – Grade 6), worked on agriculture as their main career, and decided to grow rubber tree because it was Thai economic crop with good prices. With regard to money invested into rubber farming, the farmers spent their own money and also received assistance from the Office of the Rubber Replanting Aid Fund. Their average initial investment amount was 49,653.58 Baht. The average number of family members was 5, but only two members worked on the rubber farm. This might be due to the fact that some family members were students or had other careers (disguised unemployment). Averagely, there were 70-89 rubber trees planted per rai (equal to 1,000 m2), with the spacing of 3x7 meters. The most popular Para rubber variety planted in the Northeast was RRIM 600. The alternate daily tapping system (two days in tapping followed by one day rest) was employed during the rainy and cold seasons, but the rubber trees would be given a rest in the hot season because rubber latex yield was quite low during that time of the year. Rubber farmers in Northeast Thailand produced the Para rubber latex in the forms of cup lump and raw rubber sheet. The main product was cup lump because it required easier production process and was most suitable for new farmers or those with small amount of money. After Para rubber trees could be tapped, the farmers had an average variable cost of 306.79 Baht per rai, an average fixed cost of 46.92 Baht per rai, and an average net income of 2,270.27 Baht per rai. With regard to sale of rubber products, the farmers would gather and form a group through local auction market which farmers have brought rubber before bidding day. On the bidding day, rubber is weighted and farmer got money. Also, it distributes their products to middlemen. As above mentioned, more farmers are interested in cultivating rubber trees. This could result from the fact that rubber prices in the Northeast tended to increase. High demand from international rubber consumers led to an increase in rubber prices, motivating rubber farmers to grow more rubber trees. As a result, the network marketing of rubber central markets was formed to facilitate the purchase and sale of rubber products in remote areas. There was also a development of a market network to reduce the producers’ costs of transportation of their products. Moreover, the government should play a suitable role and promote rubber plantation in the Northeast as well as control the rubber prices to ensure that they would not be too low. Moreover, the government should help control the prices of production factors, such as fertilizers, to ensure that they would not be too high.