Abstract: The non-linear fitting of thermodynamic adsorption process based on the Origin 7.0 software was not only simple and accurate, but also visually expressive. The humic acid (HA) extracted from albic soil as a sorbent was adopted to carry out the thermodynamic study of adsorbingZn²⁺ . Combined with Origin 7.0 software, the adsorption process was described in 2 ways. The results showed that: there were several similarities existed in 3 thermodynamic curves under the conditions of three temperatures (293, 303 and 313 K). At the low range ofZn²⁺ initial concentration, the adsorption curve increased approximately like a straight line, and withZn²⁺ concentration increasing, the rising level of adsorption curve became slowly, and then gradually the adsorbed capacity reached at equilibrium. In comparison, the adsorption ofZn²⁺ into HA increased gradually with increasing temperature, especially at the high initial concentration ofZn²⁺. The best description about adsorption process between HA andZn²⁺ was found in the Langmuir equation. Under the same condition, the fitting effect of self-defined parameters in the Origin software was better than the inherent equation existed in Origin itself.