Scheduler plays an important role for long term evolution- advanced (LTE-A) system to achieve high throughput performance. Existing research work on scheduler design did not fully consider non-full buffer capacity at the base station (BS) owing to the fluctuation on data volume. In this paper, we proposed a quality-of-service (QoS) guaranteed channel- aware (QGCA) scheduler with the consideration of BS buffer status to improve system capacity. The proposed QGCA scheme fully considers the required components for LTE-A scheduler, including resource grouping along with modulation and coding scheme. Moreover, we proposed an adaptively channel-aware resource grouping (CARG) method within the QGCA scheduler for improving the performance of existing resource grouping schemes. Numerical results show that our proposed QGCA scheduler and CARG scheme outperform conventional methods, especially under non-full buffer and delay-sensitive VoIP traffic.