The invention provides a plastic ampoule filled with medicinal liquid, which has the functions of blocking gas, water vapor and light and preventing drug penetration, absorption and adsorption, and a preparation method thereof. The plastic ampoule 10 for filling medicinal solution of the present invention comprises a container main body 11, a fused portion 13 closing its opening 12 and a holding portion 14 connected thereto for twisting. The ampoule 10 is formed using a parison having two or more layers, at least one of which is a material selected from the group consisting of gas transmission, water vapor transmission, light transmission, drug transmission and A functional layer that prevents at least one of drug absorption and adsorption properties. That is, the parison is extruded from a multi-layer blow mold, clamped by the lower parting die to form the main body part 11 of the container, and after filling the liquid medicine 15 therein, the opening part 12 is clamped by the upper parting die to form a fusion joint. Part 13 and holding part 14, thereby making the product of the present invention.