Deep learning models, especially those large-scale and high-performance ones, can be very costly to train, demanding a considerable amount of data and computational resources. As a result, deep learning models have become one of the most valuable assets in modern artificial intelligence. For instance, it can cost $1.6 million to train a BERT model on Wikipedia and Book corpora. It is thus of utmost importance to protect deep learning models from unauthorized duplication or reproduction. This talk will be about threats to deep learning copyright and corresponding defence techniques on copyright protection of deep learning models.