The invention discloses a light or auxin induced promoter HLP3 of arabidopsis. The nucleotide sequence of the promoter is as shown in SEQ ID No: 1, and the promoter is cloned and obtained from a genome of the arabidopsis through a PCR technology. The invention further discloses application of the promoter HLP3 in plant gene function research or gene engineering breeding. The promoter HLP3 is respectively fused with functional genes to construct plant expression vectors, and then is transferred into plants, so that inducible high expression in transgenic plants is realized. Experiments prove that after the transgenic plants are induced by light or auxin, the expression activity of a reporter gene GUS is remarkably higher than that of a control group, it shows that the promoter HLP3 is a promoter which is intensively induced by light or auxin, and it predicts that the promoter HLP3 has huge application potential in gene function research of the plants and crop genetic breeding.