Qin Dynasty (221 BC - 206 BC): In 211 BC, during building the great wall of Chins, signal tow3ers were designed at strategic points to warn the army behind the wall of any intrusion by the enemy forces. Smoke signals were used during the day and bonfires at night. It is believed that saltpeter (potassium nitrate), the main ingredient in black gunpowder, was added to the firewood.

Dong Han Dynasty (206B.C. - 220AD): People roasted bamboo to produce a loud sound that was intended to scare away evil spirits.

Sui Dynasty (581A.D. - 618A.D): A story was told that in 616 AD, during the Sui Dynasty, a flare signal, summoning reserve troops to military service was set off was found to entertain the morose wife of the emperor Yang-Ti. When the soldiers gathered, all with a sullen look on their face, the sight was so amusing that it made her laugh. Some historians believe this to be the first instance of flares being used as fireworks.
Sui and Tang Dynasties (581A.D. - 907A.D): China witnessed the invention of gunpowder, a mixture of Potassium Nitrate, sulfur and charcoal. This was found during the search for a medicine to prolong life.
IN the year of 904 AD, Zheng Fan attacked YuZhang . Gunpowder was first used in the Military.