A cascading injection locked S-band Voltage-Controlled Oscillator(VCO) array is proposed in this paper. It facilitates the VCO array configuration and enhances its scale by using cascading injection-locked method instead of traditional single order injection method. All VCOs are cascaded by coupling network. At the same time, it is easy to increase the stage of cascaded circuits. A reference signal is injected into the first VCO. The second VCO is locked through the signal coupled from the output of the previous VCO. Each reference signal is injected into the VCO through its voltage tuning port. It locks the output frequency and decreases the phase noise. Multiple VCOs are locked by one signal through coupling in between. Two cascading injection-locked VCO arrays are designed, fabricated, and measured. The VCOs output identical frequencies with similar phase noises. The phase noise of each VCO is near to -105 dBc/Hz, when the phase noise of the source is -107.28 dBc/Hz. The injection-locking method is simple and low-cost, which has future applications in phased arrays.