Abstract: The positive working condition of grassroots agricultural extension staff is of great significance for promoting agricultural technology extension performance and speeding up the agricultural modernization process. Based on the survey data of rural agricultural extension personnel in Hubei Province, this paper synthetically measured the work enthusiasm of them from three aspects: willingness to work, learning initiative, and technical guidance and service. This paper also applied the ordered Probit model and analyzed the key factors influencing the work enthusiasm based on the theory of planned behavior. Results show that, in general, the work enthusiasm of grassroots agricultural technology extension workers is between “average” and “relatively positive”, with 28.64% of them work actively or very actively, and about 20.00% of them work inactively or very inactively. Under different individual characteristics, the work enthusiasm shows obvious heterogeneity. Specifically, male workers aged over 46 years old and senior personnel with college level or above educations belong to the group of high work enthusiasm. Factor analysis shows that behavioral attitude, subjective norms and perceived behavioral control have significant influences on the working enthusiasm of rural agricultural technology extension staff and the influence degrees showing a decreasing trend in the above order. While wage satisfaction, job recognition and the sense of achievement in work are positively related to their work enthusiasm. Demonstration effects of colleagues and farmer’s trust have significant positive impacts on their work enthusiasm. However, local government’ insufficient attention and outdated technical facilities obviously hinder their work enthusiasm. Finally, this paper provides some suggestions to improve the work enthusiasm of grassroots agricultural technology extension staff, including to increase investment in agricultural technology extension funds, to establish special promotion fund, to enhance policy support, to combine economic incentives and institutional incentives together, and to strengthen the construction of trust mechanism and organizational culture.