In this paper,Northern hybridization was used to analyze the Sly-MIR167 expression pattern of tomato under cold stress.The result shows that:(1)Sly-MIR167 constitutively expressed in roots,stems,petals,fruits and leaves of tomato at 25 ℃.However,the expression trends become more greatly at 4 ℃.The result indicated that Sly-MIR167 was induced by low temperature.(2)The 35S∶MIR167 expression vector was constructed and transferred into tomato by Agrobacterium infection.The cold stress experimental results show that the transgenic lines have better growth index than that of control.Moreover,the chlorophyll content and F_v/F_m of two transgenic lines(T₂-5 and T₂-19) decreased significantly lower than that of wild type;more proline content and less MDA content in the transgenic lines than that in the wild type.Sly-MIR167 can obviously improve the cold tolerance of tomato.(3)The expression assay of target gene NF-YA1,NF-YA2 by RT-PCR demonstrated the down-regulation caused by Sly-MIR167.It indicated that NF-YA1 and NF-YA2 were negative regulated.In a word,the research contributes to provide more application prospects in transgenic tomato.