Credit markets are an essential economic institution. In developing countries, particularly in countries undergoing rapid social and economic transition, it is important to identify emerging credit demand and institute credit supply in a timely manner to facilitate economic transformation. This research focuses on the evolving rural credit market in China, where borrowing from the social network has been common but the recent economic transition has made this informal credit market inadequate in addressing rural credit needs. This research is aimed at identifying the social and economic factors that explain the farmers’ credit constraint and influence farmers’ decisions to switch from informal to formal credit markets. Using data from a household survey, we estimated both binary choice probit models and a multinomial probit model to explore the determinants of credit market choice and credit constraints. We found that the credit demand is significantly affected by household’s production capacity as supported by the fact that household size, land size, head’s education all significantly increase household’s probability to borrow, but the impact of these factors varies considerably by credit market. Transaction costs have a significant, negative effect on formal credit demand. The credit constraints analysis suggest that off-farm employment, land size and the cost of the credit are the three most important factors that increase the probability of being constrained.