This short communication reports the synthesis of carbon quantum dots (CQDs) from US anthracite and bituminous coals by oxidation in presence of ultrasonic stimulation. The CQDs formed were examined by using chemical analysis, UV-Visible spectroscopy (UV-Vis), Fluorescence spectroscopy (FL), High resolution transmission microscopy (HRTEM), and X-ray Photoelectron spectroscopy (XPS), revealing the formation of the varied sizes of CQDs ranging from about 2-12 nm. The present method could serve as a simple and a large-scale synthesis of CQDs from abundant and economical coal resources for high-end application.