Abstract: One of the most important parameters in analyzing of one structure is relative displacement of stories which is shown with drift. A lot of design codes for buildings have some limitation and never allow the structure to displace more than the acceptable amount. Actually at the time of any earthquake an extra displacement of the structure may lead to some events such as: destroying the connectors, fear of residents and destroying the whole structure. Sometimes, all structure calculated and finally, the relative displacement of the structure prepared under control. If it is more than the acceptable amount, some changing must take place and also its stiffness should enhance in facing of lateral forces.