Abstract: An anchorage system is provided for fixing the guardrail tubes for the building works. The anchorage system includes a body member having a recess, an end portion being formed thereof locations allowing to receive screws fitting therewith for be fixed in a wood casing before that the concrete be poured therein and that the casing be removed thereof, a cavity, and grooves. The recess receives an end tube provided of a rod and being formed as integral part of a guardrail tube. The end tube is blocked therein the cavity by the rod sliding therein grooves, and for that the end tube be blocked therein, the guardrail tube is rotated and fixed to the braces. The same anchorage system is also used with a fastening device for connecting a safety harness in a concrete slab.