This study reviewed the literature on QOL（Quality of Life）assessment for children with severe multiple disabilities in order to clarify research trends and problems. The author reviewed several academic papers. The following were the findings of the review: 1. The definition of QOL has not been unified; it was different for each research topic or field of research. 2. Similarly, the QOL assessment methods have not been unified; they have been developed differently for each field of research. 3. There are two kinds of assessment methods. One is a subjective QOL assessment method; the other is an indirect QOL assessment method. 4. QOL assessment needs to be subjective in principle. However, it was difficult for the researchers at PIMD to provide an answer to this question as this was an assessment of existing literature.