We report a novel structure of carbon nanowalls (CNWs) synthesized by a two-step growth method using a radical injection plasma-enhanced chemical vapor deposition (RI-PECVD) as combined with a capacitively coupled plasma chemical vapor deposition (CCP-CVD). Scanning electron microscopy (SEM) observation shows that the CNWs grown by this method exhibit a multi-branched morphology with an average wall distance of ∼20 nm and a density of ∼74 wall units/μm2, which is more than 5 times higher than that of CNWs synthesized by the single-step RI-PECVD method. These branched-CNWs are crystalline and comprised of multilayer graphene as confirmed by the Raman and high-resolution transmission electron microscopy (HRTEM) analyses. A static water contact angle of 150° was obtained for the multi-branched CNWs indicating a superhydrophobic property. A possible growth mechanism of the branched-CNWs was also proposed through the investigation of the time-dependent growth from the second step.