The 2008 Labor Contract Law of China stipulates that all employment relationships must be covered by a written labor contract. This regulation considerably strengthened employment protection for workers. Using a unique longitudinal dataset, the China Labor-force Dynamics Survey (2012, 2014, and 2016 waves), this article estimates the impact of the formal contractualization of labor relations on workers’ labor market outcomes, social insurance participation, and job satisfaction. We find that gaining a labor contract was strongly associated with an increase in salary, a decrease in working overtime hours, and greater participation in unemployment and pension insurances. In terms of job satisfaction, workers who gained a labor contract reported being less satisfied with their workplace environment and income than they had anticipated. This finding suggests that workers had higher expectations from the benefits gained through contractualization, than what they actually derived.