Taking yellowish yinghong NO.9 as the raw material , the effects of two methods, sun withering and air-blast withering, were analyzed on biochemical compositions and color value on black tea quality. The results showed that the biochemicals of water extracts, tea polyphenols, flavonoids, catechins, free amino acids and tea pigments could be easily influenced by air-blast withering, compared with sun withering. Theaflavins and theabrownines were higher for fan withering methods than that for sun withering in the samples. Tea polyphenols, flavonoids and catechins significantly decreased as well as theaflavins and thearubigins, caffeine significantly increased as long as withering time in the samples processed by two kinds of withering methods. The brightness (ΔL^*) and total color difference (ΔE^*_ab) increased, while the redness (Δa^*) and yellowish (Δb^*) decreased. The correlation analysis showed that water content of withering leaves and flavonoids significantly had positive correlation with Δa^* and Δb^*. Theaflavins and thearubigins showed a significant positive effect on Δb^*. Theaflavins had a significant positive effect on Δa^*.