The present invention relates to a gene controlling the flowering time of plants, and a method for manipulating the flowering time of plants using the gene. More particularly, the present invention relates to a LOV1 gene controlling the flowering time of plants, which is isolated from Arabidopsis thaliana, and also to a method for either delaying the flowering time of plants by overexpressing the LOV1 gene in the plants, or inducing the early flowering of the plants by repressing the expression of the LOV1 gene in the plants.