A pot experiment was conducted to study the effect of three different temperature treatments (5 ℃, 25 ℃ and 35 ℃) on the color changes and nutritional quality of purple pakchoi ‘Ziyi’(Brassica campestris ssp. chinensis Makino)，providing a suitable temperature to improve the highquality purple pakchoi in cultivation techniques. The results showed that: (1) the leaves of purple pakchoi were dark purple with the prolongation of treatment time at low temperature of 5 ℃. On the contrary, when the leaves were exposed to high temperature of 35 ℃, the color of the leaves gradually became light until the leaves became green, it was consistent with the change of anthocyanin content in leaves. (2) Compared with treatment at 25 ℃, the contents of reducing sugar, soluble sugar and total sugar in the leaves of purple pakchoi decreased gradually after being exposed to high temperature (35 ℃), but increased firstly and then decreased with the prolongation of low temperature treatment at 5 ℃, and the range of decrease under high temperature was greater than that under low temperature. Similarly, the contents of soluble protein, reducing ascorbic acid and amino acid also decreased under high temperature stress, but they increased significantly under low temperature. On the contrary, the activity of ascorbic acidperoxidase (APX), the contents of cellulose and nitrate increased gradually under high temperature stress and decreased significantly under low temperature. The results indicated that purple pakchoi leaves were affected by the different temperatures, the low temperature accelerated anthocyanin accumulation, while it was inhibited to accumulate the anthocyanin content at the high temperature. Low temperature could promote the accumulation of the contents of soluble protein, ascorbic acid and amino acid, reduce the content of cellulose, change the phenotypic characteristic of leaf color and improve nutritional quality in purple pakchoi. On the contrary, high temperature could reduce the appearance and nutritional quality of purple pakchoi.