Quasars can be divided into radio-loud quasars (RLQs; R≥10) and radio-quiet quasars (RQQs; R<10) based on radio-loudness parameter R (R = f5GHz / f4400Ã… ). Highly radio-loud quasars (HRLQs) are a subpopulation of RLQs with R â‰³ 300. This project analyzes X-ray data of 9 HRLQs at 4.0<z<5.5. We combined these 9 sources with 32 previously studied sources to form a sample of 41 sources to investigate the X-ray enhancement of HRLQs.