In our country, the Environment Protection Law has been legislated and effective since Dec. 31, 1977. In the field of the dyeing industry, there has no been established any sufficient measure required by this law. In the dyeing industry, the treatment of waste-water is a great problem and the establishment of waste-water treatment facilities is one of the most serous problems. In order to promote the efficiency of waste-water treatment, it is necessary to grasp the actual status of the waste-water, to establish and operate the appropriate capacity of the treatment facilities, and the technical standard for this purpose has to be set up. This study aims to grasp the actual status of the waste-water to promote technical rationalization and in the technical aspect to examine the basic data making the waste-water treatment effective and rational. A sample survery was conducted with the actual status of waste-water and the quality of the waste-water with the dyeing factories chosen as samples. According to the result of this study, the following conclusions were obtained. 1. Majority of domestic dyeing factories belong to medium or small enterprise, are poor, in general, in the scale of their facilities, technological standard and funds arranging capacity and are unable to set up adequate measure to the control of waste-water treatment enforced by the Environment Protection Law. 2. Dyeing industry has a comparatively long history in our country and majority of them are located in down-town areas, their factories undergo restiction in expanding and/or renovating their facilities and are to move to the outside of the city and evade establishing the permanent waste-water treatment facilities and have established the facilities as a formality. This is a problem to solve the fundamental matter of environment protection. 3. In order to prctect environment, professional knowledge is required and enterprise must have deep concern with this; matter. At present, the enterprise has neither professional knowledge nor deep concern and consequently, the enforcement of positive technical guidance and support of technology and required funds for this purpose, must be arranged from the dimension of Government policy. It is also desirable that an institution should be established so that a certain scale of industry may employ a qualified engineer in charge of environment protection duties. 4. It is an economical problem for individual dyeing industry to establish and operate its independent waste-water treatment facilities. In order to solve this problem, it is desirable that all the medium and small dyeing industries scattered in various parts of down-town should be concentrated on a certain area outside of the city as a dyeing industry complex and that the dyeing industry complex should jointly establish and operate the waste-water treatment facilities. 5. If no measure is taken to prevent dyeing waste-water from flowing into river, the water of the river will be considered highly polluted (Refer to Table 9~Table 11) and if it is properly treated, the waste-water may maintain less than COD 150 ppm provided in the Law on Textile Industrial Waste-Water Quality. According to the test of decolorizing of waste-water and test on removal of COD, the treatment by the coagulationg agents such as aluminium sulfate and ferric sulfate is most effective.