The dragon was, and still is, a powerful figure in most Asian cultures. However, what most Westerners call 'Chinese' dragons can be from any number of cultures, most prominent being Chinese, Japanese, Korean, and Vietnamese. They are also male or female. It can be difficult to determine which is which, since the art styles are so similar to the untrained eye. The easiest way to tell what country a picture, painting, sculpture, or article of clothing the dragon appears on is from, or which gender it is, is to pay special attention to the smaller details.
Across each Asian culture, the differences between male and female dragons are relatively the same. A female dragon is most easily distinguishable if she is carrying a sensu, or fan in her tail. However, if nothing is being held in the tail, there are other clues. The spikes on the female's mane generally have rounded points; also, they have thicker bodies and their snouts are straighter. A dragon carrying a war club or other club-like weapon in its tail is a male dragon. If there is nothing held in the tail, they are distinguished from the female by being longer and having a curved snout. Also, the male has a rigid, pointier mane. Check to see if the dragon you are viewing has horns. A male dragon's horns tend to be thinner at the base than they are at the tip.
The Chinese dragon, or lung, can have four or five toes. If it has four toes, then it is considered a common dragon; however, a dragon with five toes was the imperial dragon. In ancient China, anyone in posession of the image of a five-toed dragon was sentenced to death. This dragon is very precise, having a total of 117 scales.
The Korean, or mang, dragon has four toes on each paw, which can be confusing when trying to distinguish it from the four-toed Chinese dragon. The main difference between the Korean dragon and the Chinese dragon is that the Korean dragon has deer-like horns. And, if the picture is clear enough, or your view of the item at the right angle, and you have the time and patience, 81 scales can be found on the back of a Korean dragon.
Dragons from Japan, also known as tatsu, have three toes on each paw. Other than this, they do not differ from other Oriental dragons.
Vietnamese dragons are also known as ryo. Like the Chinese dragon, Vietnamese dragons have either four or five toes. A five-toed dragon is intended for imperial use, and a four-toed dragon is considered 'common'. Vietnamese dragons, unlike other Oriental dragons, breathe fire and also have wings.
Of all the differences between these dragons, they are still quite similar. Most dragons are depicted in white, black, blue, red, and yellow. And in many images of an Oriental dragon, the dragon has a pearl, its 'pearl of wisdom', held in its mouth, grasped in its claws, or tucked underneath its chin. This pearl symbolizes the power that enables the dragon to ascend to heaven.
So now you know how to distinguish whether a dragon is male or female, and whether it is Chinese, Japanese, Korean, or Vietnamese. And if you don't have any Asian art specialists hanging around to impress with your knowledge... well, your mother always cares.