A duì lián is a traditional Chinese poetic form consisting of two parallel, balanced lines—usually written on red paper and hung vertically on either side of a door or gate. The first character, duì, means 'opposite' or 'matching', reflecting the requirement that the two lines must correspond in structure, tone, meaning, and number of characters. The second character, lián, means 'joined' or 'linked', emphasizing their inseparable pairing as a single artistic unit.

These couplets are especially prominent during the Spring Festival (Chinese New Year), when families select auspicious phrases expressing hopes for prosperity, health, or harmony. They’re also used at weddings, store openings, and temple entrances. Each line typically contains five or seven characters, and strict tonal and semantic parallelism is expected—making them both literary art and cultural symbols of balance and good fortune.