ARIA is an AES-like 128-bit involution substitution permutation network (ISPN) block cipher algorithm used by Korean government. AES, the most popular block cipher algorithm, has a lot of demands for acceleration. AES acceleration is supported by AES-NI, and at the same time it has long been researched to accelerate AES algorithm on GPU. However, it is impossible to accelerate ARIA with its own instruction support and there is no available GPU implementation of ARIA. In this work, we built an OpenCL ARIA encryption library for GPUs/APUs, explore optimization strategies and their impacts, and test encryption throughputs on various platforms. Our implementation reports 104.70 Gbps encryption throughput on GeForce GTX 1060 GPU.