DUE; just, proper, sufficient, reasonable.
DILLIGENCE: attentiveness, care. The attention and care required of a person in a given situation and in the opposite of negligence.
(See Black's Law Dictionary.)

Due dilligence is, therefore, the degree of care which a person is required to take in a specific circumstance in order to avoid possible damage to himself and other persons. In besiness contracts, the term is widely used to require that one of the parties exercise due care to take into account possible risks and is generally translated into 相當的注意 or 應有的注意.

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Note added at 2001-12-27 14:45:49 (GMT)
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This is a legal term and should be translated into an equivalent or close Chinese legal term, especially when it is used in a contract. Ref. 彭金瑞等《簡明英漢法律詞典》(北京商務印書館)；陳公綽《英漢法律政治經濟辭典》；日本有斐閣《英米法辭典》(適當之注意)。