String is an important component of archery equipment to generate the elastic energy by the pulling action of archers. Elastic energy is converted as the kinematic energy of arrow after the releasing the string. Normally the string is circulated around two ends of bow limb to reduce distance between these two ends for storing the desired energy of the arrow. There is no formal standard to define the length between two ends and number of strings for installing string. The first objective of the paper is that for the same bow and length of string, how various numbers of strings as well as the spacing between the string and the anchor point affect the pulling force need be verified. The second objective is whether the failure of releasing arrow after fully pulling will result in undesired residue energy to affect the elastic energy is also needed to be studied. We utilize the precision machine to accurately control the pulling distance and to measure the associated pulling force. Based on 12 and 20 numbers of strings settings, it indicates that pulling forces are almost the same regardless of different string number and spacing settings. However, for both numbers of strings settings, we find that (1) Pulling force at 28 inches pulling distance will increase when the spacing settings increase. (2) Failure of releasing arrow after fully pulling to be 25 or 28 inches does not significantly affect the pulling force.