The Central Statistics Agency (BPS) recorded that in Central Java in August 2018 as many as 6.74 million people (39.06 percent) work in formal activities, and as many as 10.51 million people (60.94 percent) work in informal activities. During the last year, the amount of informal workers rose from 60.29 percent in August 2017 to 60.94 percent in August 2018. Most of them are informal workers whose income is uncertain, so priority of their work is how to make money to meet everyday life. It is rarely of them who have thought to become employment social security participants. The research method used in this study is juridical normative. Data sources used were secondary data covering primary legal materials, secondary legal materials and tertiary legal materials. Analysis technique used qualitative analysis methods with interactive analysis model. The results show that the existing conditions in Central Java represent very few informal workers become participants of employment social security voluntarily without sanctions for non-participation of employment social security. Meanwhile the government has not allocated the budget to provide employment social security yet for weak and poor informal workers. This will certainly make it informal workers whose conditions are weak become weaker or increasingly less well-off economic and social, when informal workers experience economic risks and other social risks, hence the condition of informal workers will be increasingly worse off and not prosperous. However, the informal workers really are State’s asset, since they still exists and is still able to build and sustain the Indonesian economy when Indonesia experiences an economic crisis. Obstacle factors of employment social security law protection programs for informal workers in Central Java Province are low levels of education of informal workers, low and uncertainty income, reluctance to pay contributions and high unemployment in Central Java.