This paper deals with a mobility of the single compliant joints and entire compliant mechanisms. The compliance of the joints and the mobility of the compliant mechanism can be increased by variations of geometry as well as material type of the joints. Therefore the mobility of three kinds of compliant joints with different geometrical shapes (beam joints, film joints and notch joints) will be researched. The mobility of the compliant joints made of different material types (plastic joints, silicone joints) will be also researched. The mobility of compliant mechanisms will be analyzed by using of the Roberts-Tchebicheff mechanism which coupler point can be guided on an approximately rectilinear path.