Abstract: For the sound insulation of a double-leaf partition, stud creates a vibration transmission path between leaves that can often be more critical and also more important in mid-frequency range than the airborne path through the cavity. As partitions with light-weight steel stud are more commonly used in the building construction, therefore studies on the sound insulation effect of such stud have been conducted. A model of considering the steel stud as an elastic spring and its lateral stiffness as a parameter in the sound insulation index prediction of such partition initialed by Gu and Wang (1983) has been widely studied during past decades. Experimental results of different stud profiles have been reported from different testing laboratories and give more information to understand the stiffness effect of the stud on the sound insulation of the partition. After a review of this subject in the paper, it has been pointed out that a critical problem on the determination of the stiffness of the connecting elements in the double panel partitions needs to be investigated further.