(EN) The present invention provides a high-modulus glass fiber cornposition, a glass fiber and cornposite rnaterial thereof. The high-rnodulus glass fiber cornposition cornprises the following cornponents expressed as percentage by weight: 42-56.8% of Si02, 15.8-24% of A1203, 9.2-18% of Mg0, 0.1-6.5% of CaO, greater than 8% but less than or equal to 20% of Y203, 0.01-4% of Ti 02, 0.01-1.5% of Fe203, 0.01-1.5% of Na20, 0-1.5% of K20, 0-0.7% of Li20, 0-3% of Sr0, and 0-2.9% of La203; wherein, the total weight percentage of the above components is greater than or equal to 98%, and the range of the weight percentage ratio C1=Y203/Ca0 is greater than 2.1. The composition can significantly increase the modulus of glass fiber, significantly reduce the refining temperature and bubbles content in rnolten glass; it can also rernarkably irnprove the cooling performance of glass fiber and effectively reduce the crystallization rate. The cornposition is suitable for large-scale production of high-rnodulus glass fiber.
