In fusion experimental reactors such as ITER, the in-vessel components such as blanket and divertor are actively cooled and a large number of cooling pipes are located around the core of reactor, where personnel access is prohibited. Mechanical pipe connectors are highly required as standard components for easy and reliable connection/disconnection of cooling pipe by remote handling. For this purpose, a clamping chain type connector has been developed with special mechanisms such as plate springs and guide structures so as to enable concentric and axial movement of clamping chain for easy mounting and dismounting. The basic performance test of a prototypical connector for a 80-A pipe shows sufficient leak tightness and proof pressure capability as well as simple connection/disconnection operation. In addition to the clamp chain type connector, design efforts have been made to develop a quick coupling type connector and a preliminary model of air-actuated quick connector has been fabricated for further investigations. This paper gives the design concept of mechanical pipe connectors such as clamping chain type and quick coupler type, and the basic performance tests results of clamping chain type connector. (author).