China is the execution capitol of the world, and not just because it has the largest population. But, slowly, but meaningfully, it is cutting back on executions. From 10,000-15,000 executions a year, the numbers may have fallen as low as 7,500 and could fall 20%-30% with new legal reforms. Exact information on executions in China is a state secret and even Amnesty International can only specifically identify a little over 1,000 executions a year even though it knows that this is just the tip of the iceberg. The coming Olympic games in China are only one factor in the change in the still evolving legal and political system of China.
At 7,500 executions a year, China's execution rate is comparable to having 1,875 or so executions a year with a population equal to that of the United States (i.e. an order of magnitude more than the U.S. rate which has 50 executions a year), or 144 executions a year in Texas (even Texas doesn't have an execution rate that high).
There may be a few small Islamic countries with higher execution rates than China, but not many. Even with a 20-30% drop, China's execution rate will still be very high by international standards. But, a 20%-30% drop in Chinese executions would reduce executions worldwide by more than the total number of executions carried out by every other country in the world combined that still has the death penalty. In 2006, there were fewer than 600 executions carried out in all countries other than China combined.