Vietnam is an agricultural country with 70 percent of the population living by agriculture. The crop production sector plays an important role in agriculture remarkable contributions coming from the plant breeding sector. In years of subsidization with big government investment capital, an official seed system (involving companies, public research institutes, and universities) produced a large quantity of seed for farmers. However, this official system has its limitations. For example, it only provides farmers with 10-20 percent of the rice seed that they need annually. This shows the important role of the farmers’ informal variety system, which still supplies the vast majority of seed for production, even for rice, which is a very important commercial crop in Vietnam.