About transit visa/stopover

You do need a transit visa if you will exit the airport, but you may also apply for a stay permti on your arrival at the airport.

Thank you for your reply.
I had been through the China Embassy Site.
So for obtaining the Transit visa I have to Submit
1. The Application Form
2. The Supplementary Application Form
3. A recent passport-size color photo with white background stuck on the application form
and what else?
Can I get the one for 1 month? because I will return after 20days and the return ticket shows that I have to wait again for 14 hours in Beijing for the connecting flight.
What is the fees for it if I ask for a rush service for the same working day.

Documents listed above is enough. But note that transit visa is valid for 3 months and it allows 7 days stay in China. For you, you can apply for a double entry. Fee is Yen 9,000 under urgent service. Visa can be picked up on the 2nd or 3rd working day of application. The same day service is not available.

Ok, I have understand it.
Help me with some more information.
I will be in presence while make the Visa Application.
Does China Embassy has the service to send the Passport via mail?

If the Embassy doesn't have the service to send via mail.
And if I submit the papers tomorrow(24th oct,wed) for a normal process(as it is written 4 working days), then usually I will get it in 29th oct, monday.
Is that right?

Yes, you are right. But if you can not go for collection in person, you can pass your receipt to someone else and let him/her pick-up your passport on your behalf.