Abstract: Policy changes will take effects on public pressure and spatial distance. Generally, the former decreases stock-price synchronicity and the later increases it. How these two factors affect the stock-price synchronicity through environmental information disclosure has become a problem needed to be solved. From the prospective of policy changes, the paper selects manufacturing firms in china during 2004-2006 and 2009-2011 as samples to investigate the effects of environmental information disclosure on stock-price synchronicity. The result shows that, before the implementation of the environmental policy in 2008, remote firms’ environmental information disclosure is related to stock-price synchronicity negatively. However, after the policy implementation, the relationship becomes positive. As for the firms with short distance to the city center, the effect is insignificant. Therefore, with an increasing public pressure, firm location plays a vital role of mediation in the process of environmental information disclosure affecting stock-price synchronicity, which should be paid enough attention by the supervision department.