Not only is antique china beautiful, it can be very valuable. Its value depends on a number of things, the most important ones being its age, manufacturer, and condition. The mark or signature usually found on the back of the china will tell you how old it is, where it was made and who made it. It's important to realise that although your antique china may be very rich in sentimental value, its true market value really depends on the above factors. As a general rule, the more rare a piece of antique china is, the more collectors will pay for it.
Find the mark or signature on the plate, teacup, saucer, pitcher or whatever other type of china piece you have. This is usually found on the bottom of the piece. Look for the name of the country in which the piece was produced and the year it was made. For older items, especially those made before 1890, when the United States passed a law requiring this information, you may not be able to determine the country of origin or the manufacturer just by looking.
Examine your china closely using a magnifying glass. Check for scratches, chips, smudges, stains, cracks or anything else that might decrease the value of the particular piece. Do not attempt to repair these damages on your own, as you could inadvertently lower the value of the china even more.
Carefully clean your piece using a soft cloth and some mild dish detergent. Be careful not to scrub any of the paint off, which can be very delicate if it's a very old piece. Pat it dry and keep it in a safe, cool place.
Try to identify your piece using an official antique-china pricing guide. Kovels on Antiques and Collectibles, for example, keeps an extensive pricing list for all sorts of antiques, including china. You'll find photos of specific marks and signatures so you can compare them to the one on your china.
Take several high-quality digital photographs of your piece. Make sure to take a close-up shot of the mark or signature, as this is the most important information for the appraiser. Take photos of any mark, blemish, crack, etc. as well.
Consult a professional appraiser. Your best bet is to rely on personal recommendation and find someone with extensive experience and quality references. Provide the appraiser with all the relevant information, including where and when you acquired the piece, its condition, etc. A good appraiser will probably request to see the piece in person, so make an appointment to have him or her inspect it.
Weigh your options in consultation with the appraiser to decide whether or not to sell the item and when to do so. Some pieces may increase in value over time, while others may not. It all depends on the particular piece.
Do not use any harsh soaps or detergents when cleaning the china, as these can seriously damage it.