Hydraulic jar (up / down) designed to use accelerator and flow sub form a coiled tubing short heavy string. The Jar delay device let the energy stored in the stretched and elongated string accelerator, when the energy released will have a great impact, generating shock effect, loose card tool stuck. Up jarring Lowering drill string to make drilling jar closed completely (in locking position), elevating drill string by the order of small tonnage to larger tonnage, which make spring and hydraulic cylinder delay, when mandrel move to a position and become release resistance, the spring force stored in drill string will transfer to upforward energy and up jarring. Repeating the above several times can force tool to produce continues up jarring. Down jarring Move up and down the drill string to make drilling jar closed completely (in locking position), lowering drill string to make spring compressed and stored energy. When pressure of jar is larger than the desired lower unlocking force, grapple will slide out from mandrel to release the locking and make down jarring. Repeating the above several times can force tool to produce continues down jarring.