The easiest way for such a trip is to get to Moscow first: for example, on the fast train 147B for 3, 5 hours at a price of 500 RUB per ticket. Then, a direct flight Moscow-Beijing with a duration of 7, 5 hours by plane "Air China" (Air China) at a price of 12 700 RUB per person.

Cheaper, but much longer option - first by bus from Rostov to Moscow for 5 hours and about 200 RUB, and then by train to Beijing for slightly more than 6 days - but the ticket price starts from 6,000 RUB (in a reserved seat). Also on trains you can travel from Rostov the Great to Beijing via Kirov and Perm - this journey will take approximately 6, 5 days

If you need, for example, to get to Shanghai, then from Moscow there is a flight to Urumqi airport, from which already domestic flights you can fly to Shanghai. And in Hong Kong, you can also fly from Moscow's Sheremetyevo airport, having previously arrived there from Rostov by bus or train. Alternatively, you can take the train to Novosibirsk and then by plane to Hong Kong (this way will take you 2, 5 days)