Abstract: In view of the problem of badly effect acidizing of Linnan Oilfield,the main influence factors of acidizing:influence of formation temperature,influence of secondary precipitation of iron ion and influence of alteration of deeper layer were analyzed in this paper based on the geological characteristic of reservoir.Aimed at these problems,a kind of high quality slow-reacting acid was selected that had distinguishing feature as:high solvent compatibility with formation,effective slow-reacting function,ability to prevent secondary precipitation of iron ion effectively and fine compatibility with formation water etc.through the laboratory research.The technology of adding was optimized,and the technology in discharge was completed.It is shown that the effect of aciding was improved after field practical application.