Electrodeposition of Tin (Sn) is studied in the presence of ethylenediamine tetrakis(ethoxylate-block-propoxylate) tetrol (ETT). Cyclic voltammetry (CV), chronoamperometry, and chronopotentiometry are conducted to characterize the electrochemical behavior of Sn with the addition of ETT. Several influencing factors such as the ETT concentration, rotation rate, and potential scan rate are systematically investigated, and it is found that ETT suppresses Sn deposition at a certain negative potential range due to a potential dependent adsorption of ETT. This adsorption of ETT is further dependent not only on the empty surface fraction but also the occupied fraction or surface coverage. Moreover, various additives containing different functional groups of ETT are used to determine the key structural component for the inhibition effect.