Benefiting from the 60 GHz technology, physical machines in advanced cloud centers are connected by not only the conventional wired links but also the wireless communications. The 60 GHz millimeter-wave (mmWave) introduces valuable advantages into cloud centers including flexibility, scalability and high rate. Nevertheless, mmWave is constrained by directional communications, i.e., a wireless link is connected if and only if two directional antennas face to each other. This constraint introduces a new problem in cloud service: the virtual machine (VM) placement should consider the real-time connectivity if communications are required between VMs. Otherwise, rotating the antenna costs additional delay, resulting in performance degradation. To address this problem, we propose a novel connectivity-aware VM placement (CAVMP) specialized for 60 GHz wireless cloud center. The core of CAVMP is to dynamically place VMs in order to improve the utilization and avoid overloads while taking the connectivity state into account. We build a 2-rack cloud to measure the connectivity feature of mmWave communications. In addition, we conduct extensive simulations to evaluate CAVMP. Performance results demonstrate that CAVMP significantly outperforms existing VM placement schemes in wireless cloud center.