本研究係建構一個涵蓋徵納雙方的租稅侵蝕模型，在納稅義務人及政府部門下的最大化行為下，推論納稅義務人與政府部門的行為關聯。嗣後再進一步以比較靜態分析方式觀察邊際稅率、懲罰倍率與申報所得改變時，對徵納雙方行為的影響。研究則發現邊際稅率與懲罰倍率變動，對納稅義務人自我保險的影響均為正向，即提高邊際稅率與懲罰倍率都會刺激納稅義務人自我保險支出的增加。不過對政府部門而言，邊際稅率與懲罰倍率的調整效果則是不明確的，這兩個效果都必須比較外生參數對查核支出的直接效果，以及透過自我保險行為調整後的間接效果孰大孰小，才能判斷。至於申報所得變動，與納稅義務人自我保險為同向關係，與政府部門的查核支出為反向關係，則是較近經濟直覺的結果。

　　　　　This research constructs a general tax evasion model to explore the interaction between self-insurance of tax-payer and audit effort of government. Results of comparative static analysis show that self-insurance perform a positive relationship with both marginal tax rate and sanction rate. In the other word, higher marginal tax rate or sanction rate would lead to more self-insurance of tax-payer. But the effect is ambiguous for the audit effort. It depends on the magnitude of the direct effect of tax audit expenditure and the indirect effect of self-insurance. Regarding the reported income, higher reported income would inspire self-insurance of tax-payer, and reduce the audit expenditure intuitively.