Looking at what the UN think, I've glanced the statistics for homicide and death by violent crime. I doubt there are any international statistics kept for burglary and assaults so death by violent crime is what I'll have to work with.
Crimes are PER 100,000 people. I'll include the overall figures for the stat fans as well as the overall UN rating.
These figures are from 2010 as the next compilation wont be complete until 2015 is over.
The UN have taken into account war, political uprisings, loss of figures and have used panels for the smaller nations who do not keep records.
The figure to keep in mind is in 2010 in China 13,410 people died as a result of violent crime. That gives an average of 1.0 (1 person per 100,000)
Looking at where people on this forum are likely to come from we can compare:
South Africa / 16,259 / 31.0 p100k
USA / 14,827 / 4.7 p100k
Russia / 133,120 / 9.2 p100k
Brazil / 50,108 / 25.2 p100k
Taiwan / 686 / 3.0 p100k
Looking at those countries you should be able to stroll around China in the knowledge that you are in a safer country than your homeland. A safer COUNTRY but not necessarily a safer AREA. I can't imagine there being much violent crime if you're from Bum Fart in Siberia for example.
This would also be the case if you are from pretty much anywhere in South America, Africa or South-West or South East Asia judging from the stats available, with the odd exceptions.
When looking at Europe though things aren't as clear cut:
Britain / 670 / 1.2 per 100k
Portugal / 122 / 1.2 per 100k
Poland / 499 / 1.2 per 100k
Serbia / 112 / 1.2 per 100k
Belgium / 182 / 1.6 per 100k
France / 665 / 1.0 per 100k
Spain / 364 / 0.8 per 100k
Germany / 662 / 0.8 per 100k
Holland / 145 / 0.9 per 100k
Italy / 530 / 0.9 per 100k
It is with those kinds of countries that China is much more comparable in terms of death by violent crime.
Therefore if you are a Brit or an Italian (Australia and New Zealand were similar to Europe's figures) you should stroll round in China as you would back home, taking the normal precautions, you are in a similar environment per violent deaths.
As for robbery, assault etc there are no figures I can print, maybe you could find them yourself. But I would IMAGINE that in the countries I outlined you are more likely to be a victim of those sort of crimes than here. Although that is my opinion from visiting some of them, only my opinion.