The Drilling Jar which is connected with drill tool and worked with drill string is a down-hole stuck freeing tool in drilling operation. It integrates upward and downward jarring, and its delay function allows the drill string to fully stretch and store energy prior to impact release for optimal impact. During the drilling operation, the operator can free up or down the impact force by lifting or lowering the drill on the ground, and can adjust the impact force within the allowable range. The drilling jar is reliable, easy to use and operate. (KayGot also supply anti-sulfur drilling jar which made of high quality imported anti-sulfur materials). According to the structure can be divided into Mechanical Drilling Jar Hydraulic Drilling Jar, Mechanical-hydraulic Drilling Jar.