I am firmly of the belief that when in a particular country you should - must - obey that country's laws. (Indeed, part of my reasons for supporting Gary Mckinnon in his campaign not to be extradited to the Us is because anything he did, he did on British soil.)
This does not, however, excuse the use of the death penalty, to which I am always 100% opposed. Whether it acts as a deterrent, rids society of scum, thins out the prison population or simply provides society with revenge, taking a life is always morally wrong. I am sometimes in favour of life sentences, which mean lifetime imprisonment. If this was done more often then I don't think there would be the public clamouring for the death penalty that there is from time to time in the UK.
But it is always wrong to kill and China is quite simply wrong to do so. Even more bizarre to me is the way in which liberal, advanced democracies like the USA and Japan practice it.
The issue is moral, simple and just. Punish but do not kill.