May I send invitation letter and passport +visa copy via email directly to the Chinese embassy in Rome? (If yes please give email address)

Sorry, the Chinese embassies don't accept applications by post. If you are in Rome, than go to the embassy and apply in person. If you are in Ukraine, I think you should go to apply from the Chinese embassy in Ukraine too.

May I know which type you are going to apply? If it is a L type, the invitation letter doesn't need any stamp.

It is for my mom, she is in Italy. She needs regular tourist one month visa, to visit me in China during Chinese New Year holidays. She will stay with me. So as I understand I need to write invitation letter (no stamps required) attach my passport and visa copy and my address registration paper. Then mail it to my mom in Italy and she will go to the embassy and apply in person. Is it right?

Wow, you know clearly about everything. But you don't need to mail it to her actually. A fax to her is OK.