This chapter describes temporal and regional variation in pollution law enforcement in China. It shows that over time there has been an absolute growth in the frequency and stringency of sanctions. However, most importantly, we find that enforcement does not match pollution or industrial growth. And as such, the increasingly stringent national policies and extra investment have not sufficiently lifted enforcement to meet China’s environmental challenges. Moreover, central level influences have not yet been able to overcome the immense regional enforcement disparities. Instead we see a split is occurring, with stronger enforcement the richer coastal and municipal level provinces and weak enforcement in less developed regions. Potentially, this can create an institutionalized system of domestic environmental injustice where the rich can benefit from a better environment while outsourcing pollution to the poor.