The research on the relationship of mineral associations constitutes the basis of revealing metallogenic geochemical conditions and is also an important aspect in the study of the formation environment, thus having great significance for the development of the metallogenic theory. With the Haigou gold deposit as an example, the authors initially determined its physical and chemical conditions. Its metallogenic process can be divided into four stages: the stage of quartz-K-feldspar, characterized by alkaline nature (pH=7.1～9.2) and weak oxidation environment to weak reducing environment (Eh=-0.3～+0.5 V); the gold-quartz-pyrite stage, belonging to intermediate-acid weak redox environment; the gold-polymetallic sulfide-quartz stage, characterized by acid (about 4) and weak reducing environment (lower than -0.2 V); the gold-quartz-carbonate stage, characterized by the gradual transition from pH=4.5 to pH=5.3 with the decreasing temperature, accompanied by the transition of the metallogenic Eh value from weak reduction (-0.3 V) to weak oxidation (+0.5 V).