With mineral mining and smelting, industrial “three wastes” emissions and other reasons, heavy metal pollution is more and more serious in Chinese farmland soil. It has been one of the hot issues that how to predict and evaluate the bioavailability and toxicity of heavy metals in soil in recent years. The Terrestrial Biotic Ligand Model (t-BLM) is a mechanism model to predict the bioavailability of heavy metals. It assumes that heavy metals access to living organisms and bind to biological sites with formation of biotic ligands. If biotic ligands reach a certain concentration, they will produce toxicity to organisms, which can determine the bioavailability of heavy metals. This paper discusses the research methods predicting or evaluating bioavailability and toxicity of heavy metals, the basic principles of t-BLM, and research progresses of t-BLM predicting soil metal bioavailability/toxicity tested by plants, animals and microorganisms. Besides, some problems in t-BLM theory and application are presented.