The mechanism of pullout resistance of compression anchor is analysed. This anchor is developed through the field pullout tests and the laboratory element test. The compression anchor is characterized by decrease of progressive failure, simple site work, economy and durability compared with tension anchor. The characteristics of compression anchor, compared with tension anchor. mainly are summarized as follows ; (1) The plastic displacement of anchor body is very small during pullout of anchor. (2) Total anchor length decreases by the shortening of free length; (3) The progressive failure is decreased.; (4) The safety factor for pullout resistance increases with time after construction of anchor.