This paper describes new general multi-mode non-destructive testing (NDT) of composite materials and bonded structures for detecting discontinuities (defects) , the only multi-mode one of its kinds. This technique which is based on sonic and ultrasonic testing performs five different modes of testing to detect disbond, unbond, delamination, porosity, crushed core and other defects in composite materials and bonded structures. It equally suits for applications in manufacturing, maintenance and repair of composite materials and structures which almost include them in common use now availability. Good repeatability and reliability have been found. This paper discusses the principles of the five sonic mode constitute multi-mode sonic general bondtester and demostrates the vast range of propect for general NDT from our and our internal and external comrades* much practical experinence.