Breeding is a feature which enables the player to reproduce their dragons, while generating different varieties of dragons. This allows players to acquire dragons without resorting to buying eggs with gems. Other purposes of breeding are:

• Complete collections in Dragon Book.
• Acquire better dragons for Combat & Earning.
• Generate income and experience by selling hatched dragons.

Trivia

• Approximately 6:30, September 23, 2012 in Tuesday, an official update in Dragon City's Facebook page showed that Rarity Boost raises the chances of getting a Rare, Legend or Pure Dragon is increased by 50%.
• The breeding times have been changed, before the breeding time got calculated by counting the parents breeding time together. Now the breeding time will be similar as the hatch time.
• Since August 2012, there is a significant possibility of acquiring a Pure type from two legendary dragons.
• The breeding system is similar as that from pokémon games.
• The only dragon in the Generation III-b is the   Poo Dragon (1)

.