PURPOSE: To improve the fixability and workability of a marking pin used for indicating a boundary, survey point, buried object, etc.

CONSTITUTION: A marking pin is constituted of a cylindrical pin body 2 and pin 3 and the cylindrical pin body 2 is inserted into a hole bored into the ground at the installing point and, when the pin 3 is driven into the cylindrical pin body 2, the slit part 7 of the cylindrical pin body 2 is expanded. Therefore, the marking pin hardly comes out of the ground even when the pin is subject to vibrations and, at the same time, no mortar, adhesive, etc., is required at the time of fixing the pin 3 in the cylindrical pin body 2.