Abstract—This study is concerned with comparative analyses and modeling of both tap-water and pneumatic drive McKibben type artificial muscles. McKibben type pneumatic artificial muscles have been widely used in various fields, especially medical and welfare fields. On the other hand, tap-water drive muscles are proposed because conventional pneumatic muscles require a compressor to generate compressed air. In this paper, to examine some static and dynamic characteristics of them such as contraction ratio, time-delay, and time constant, an experimental setup, which can be used to control the tap-water and pneumatic drive muscles, is constructed and then the differences on the characteristics of them are examined by comparative analyses. It is useful to investigate the characteristics in order to figure out the availability and suitable applications of them. In addition, difference on modeling are investigated by using system identification technique. As a result, the identified model of the pneumatic drive muscle is more complex than the model of the tap-water drive muscle because of nonlinearity due to compressibility of working medium.