Ms.francesca, you can apply for business visa in Italy or Hong Kong. You can get your visa on the fourth working day counted from the date of submission. The required documents you need are:
1/ one completed visa application form affixed with one recent photograph for passport
2/ your passport valid up to at least six months with blank visa pages.
3/ The original version of visa notice sheet or fax from an authorized Chinese Government Department or Government-authorized company
4/ Invitation letter from a company in China.
5/ if available, return air ticket or hotel booking can also be provided.

If you obtain a double entry business visa, you have to go out of China after 30 days of stay duration.