【Objective】Zinc (Zn) is an element essential for plants and animals, but becomes a pollutant of heavy metal element when it is too much in the soil. It is, therefore, of great significance for researchers to study forms and availability of Zn in black soil to protection of the agro-eco-environment of the black soil region, a major agricultural producing one of China. 【Method】Based on the data of a 13-year field experiment, designed to have 5 treatments, i.e. no fertilizer (CK), chemical fertilizer (NPK) and chemical fertilizer plus different amounts of organic manure (NPK+OM₁, NPK+OM₂and NPK+OM₃), in the black soil region, transformation and availability of Zn in the soil were analyzed with physical-chemical methods. 【Result】Results show that CK was as high as 1.96 mg kg^-1in DTPA-Zn content, Treatment NPK, increased Ex-Zn and AFeo-Zn contents, and decreased Min-Zn content, thus improving the availability of soil Zn up to 3.3 mg kg^-1, but did not have much effect on total Zn. Treatments NPK+OM₁, NPK+OM₂ and NPK+OM₃ all significantly increased all forms of Zn in content, except for Min-Zn. About 37.5%～55.5% of the input of Zn with organic manure was stored in the soil as AFeo-Zn, and the content of available Zn in the soil increased with increasing organic manure application rate and peaked up to 14.5 mg kg^-1 in the field experiment In terms of Zn²⁺ adsorption strength and capacity, the 5 treatments displayed an order of NPK+OM₂ ＞ CK ＞ NPK+OM₃ ＞ NPK ＞ NPK+OM₁, with Zn²⁺ adsorption rate and desorption rate varying in the range of 25.9%～72.1% and 4%～25.3%, respectively. Treatment NPK caused soil acidification, thus reducing the Zn²⁺ adsorption strength and capacity of the soil and making adsorbed Zn²⁺ more desorbable, while the addition of organic manure in fertilization, though unable to inhibit soil acidification, did retard the declining trend of the Zn²⁺ adsorption strength and capacity to some extent, and made absorbed Zn²⁺ harder to desorb from the soil with increasing organic manure application rate. On the whole, black soil is relatively high in available Zn content, and in Zn²⁺ adsorption strength and capacity, too. Long-term application of chemical fertilizers acidifies the black soil, thus transforming Min-Zn into Ex-Zn and AFeo-Zn in the soil; Zn in the applied organic manure is stored in the soil as AFeo-Zn. 【Conclusion】Long term application of chemical fertilizer decreases Zn²⁺ adsorption strength and capacity of black soil, while addition of a certain amount of organic manure in fertilization may retard the trend.