Background : Angelica gigas is a biennial or short lived perennial plant found in China, Japan, and Korea. The root of Angelica gigas has been used in oriental traditional medicine and is marketed as a functional food product in Europe and North America. Cham-Dang-Gui (Korean Angelica, the dried root of Angelica gigas Nakai (AGN)) has been principally cultivated in Korea and used as a Korean medicinal herb. It contains several chemicals, such as pyranocoumarins, essential oils, and polyacetylenes. Methods and Results : Fresh Angelica gigas Nakai was purchased from Pyeongchang (Korea). Standard samples of D, DA were obtained from Korea Promotion Institute for Traditional Medicine Industry (Gyeongsan, Korea). Soluplus was purchased from BASF (Ludwigshafen, Germany). AGN was dried in the oven at 55°C for 24 h and cooled at room temperature. The AGN sample was then stored at 4°C until milling. Oral solid formulations based on Angelica gigas Nakai and Soluplus were prepared by the hot melt extrusion (HME) method. AGN was pulverized into coarse and ultrafine particles, and their particle size and morphology were investigated. Ultrafine AGN particles were used in the HME process with high shear to produce AGN-based formulations. In simulated gastrointestinal fluids (pH 1.2 and pH 6.8) and water, significantly higher amounts of the major active components of AGN, decursin (D) and decursinol angelate (DA), were extracted from the HME-processed AGN/Soluplus group than the AGN EtOH extract group (p < 0.05). Based on an in vivo pharmacokinetic study in rats, the relative oral bioavailability of decursinol (DOH), a hepatic metabolite of D and DA, in administered mice was 8.75-fold higher than in AGN EtOH ext-treated group. Conclusion : Soluplus-included solid formulation prepared by HME can be a promising carrier for oral delivery of phytochemicals. These findings suggest that HME-processed AGN/Soluplus formulation could be a promising therapeutic candidate for oral bioavailability.