Abstract: Generative Pre-trained Transformer 3 (GPT-3) is a relatively new artificial intelligence model with powerful functions. This project was an attempt to use GPT-3 in English (as a second language) writing and integrate artificial intelligence tools into instruction. It also explored the relationship between artificial intelligence tools and English writing proficiency together with creativity. An experiment involving 15 subjects was carried out on two Saturdays. The subjects performed two argumentative writing tasks, one with artificial intelligence assistance and the other without. After the experiment, they were asked to complete two questionnaires and one interview. Their writings were scored from five aspects: grammar and collocation, argumentative structure, argument novelty, proof adequacy, as well as lexical and syntactic use. The result showed that grammar and collocation improved significantly after the AI assistance (p=0.0062), and the other aspects, though not reaching the significant level, also improved to different degrees. This suggested that artificial intelligence assistance had a positive effect on English writing proficiency and creativity to some extent, which could inspire the following studies in relevant fields.