A cable management arm of a server rack includes two cable frames, two first connecting bases and two first connecting members. The cable frames are pivotally connected with each other as a whole, and the first connecting bases are installed between a rear end of a slide and the server rack, and the first connecting members are installed at open ends of the cable frames respectively. A first snap portion designed on a first elastic plate of the first connecting member is snapped into the first connecting base by the elasticity of the first elastic plate and provided for accommodating at least one connecting wire. The cable management arm may change its length as the slide is stretched or pushed, and the structural design of the first connecting base and the first connecting member is simplified significantly to lower manufacturing costs and facilitate installation and removal.