From CNN World:
China is the global leader for the number of corrupt officials who are sentenced to death, and actually executed each year. But, judging by the seemingly endless "public demand" for this kind of punishment and the surging popular anger, it would seem that there is actually not enough of it.
But it gets complicated:
The current level of corruption in China is systematic and widespread. It is so entrenched that honest officials are now part of a minority that risks being left behind. It is a system where corruption is the rule rather than the exception, and it is thus not an exaggeration to say that transparent officials are victims in a country that lacks democracy, supervision, and has a weak judicial system. This means that, no matter how great the anger of the public, it will not be sufficient to put a stop to corruption.
The death penalty can also be a political tool — people who do not have a protector, or who irritate their superiors, or who get caught on the wrong side, are often chosen as a scapegoat. Everyone can be a victim: once you lose your footing in the political power struggle, the accusations of corruption and decadence are very likely to fall on you.