The gates of the 38th annual Prince William County Fair, billed as the largest event of its kind in the state, will open at noon Aug. 14 and will continue through Aug. 22 with a midway, daily entertainment and more than 5,000 exhibits.

The fair, which last year drew nearly 100,000 spectators, is sponsored by the Prince William Veterans Farm Club.

The Herriott Family Trained Animal Circus will entertain daily, highlighted by an equestrian show, and the Robinson Family will offer a country-western show twice a day. The midway will feature food, games and 40 rides, including "Kiddieland" rides and a 110-foot Ferris wheel illuminated with more than 6,000 multicolored computerized lights.

Besides dairy and beef cattle, and swine, goat, sheep, pony, poultry and rabbit exhibits eligible for prizes, there will be a pet show in which prizes will go to the owners of the best groomed cat and dog. In addition, prizes will be awarded to the cat with the most beautiful eyes and the one with the longest tail, and to the dog with the fattest face and the one with the biggest smile. There will also be a baby contest and a Miss Prince William beauty pageant.

Other events include a tractor pull, a stunt vehicle demonstration, a demolition derby, mud wrestlers and professional wrestlers.

The $7 admission price covers parking, entertainment, including grandstand shows, and unlimited rides on the midway, which will be open from 2 to 11 p.m. daily. The fairgrounds are on Rte. 234 seven miles south of the I-66 Manassas exit and 15 miles north of the I-95 Manassas-Dumfries exit. For information, call 368-0173.