The document presents a novel approach to automatic keyphrase extraction from scientific articles using a combination of a fact-based sentiment feature and a semi-supervised method that integrates both supervised and unsupervised techniques. This approach aims to address the challenges of distinguishing keyphrases from non-keyphrases, improving extraction accuracy by recognizing the sentiment context of keyphrases often found in neutral-to-positive statements. Evaluation results indicate that the proposed method significantly enhances keyphrase extraction performance, demonstrating the effectiveness of fact-based sentiment in identifying keyphrase relevance.