This paper explains the concept of computer virus, introduces the reasons why computer virus occur and types of the virus, analyzes the characteristics of computer virus, and probes into how tax authorities to prevent computer virus from the technology level and application level.

Tax Planning at present is on the rise in our country,it has attracted the attention of both the theoretical circles and tax authorities.

The realization of the right of subrogation by the tax authorities requires compliance with the contract law and other related laws.

The paper firstly analyzes the influence which asymmetric information between taxpayers and the tax authority produces.

Several two-player dynamic game models were studied co ncerning export duty refund cheating between a tax agency and an export company in the case of complete information and imperfect information.

Right of subrogation in tax is the right by which the tax agency of a country can executes the right of a debtor on behalf of taxpayers when taxpayers do not pay their tax on time.

On Construction of Harmonious Interpersonal Relationship Inside Tax Organ;

This paper expounds on the meanings of taxation income estimation and estimating methods,analyzes the causes for which county-level taxation affairs departments should employ the estimating method of summarizing main tax paying enterprises,and puts forward countermeasures for county-level taxation affairs departments to do well in the estimation of taxation incomes.