A native of Changgu (??, modern-day Luoyang, Henan), Li was discouraged by some of his contemporaries to take the Imperial Examination owing to naming taboo: his father's name happened to sound similar to Jinshi. Encouraged by Han Yu, who admired his talent, Li took the examination, but failed it. Despite his distant royal ancestry , Li died a petty and poor official at the age of 27. There is some debate over his actual dates but according to Frodsham (1983) "the weight of evidence suggests that he was born in a Horse year, since he wrote no less that twenty-three poems in which the horse stands as a symbol for himself".

About 240 poems survived. His works were admired by the poets of the late Tang Dynasty. His collected poems were prefaced by Du Mu, and a short biography was written by Li Shangyin. Although his works were admired by many during and since his life time, they were not accepted in the canonical tradition: none of his poems made their way into the popular anthologies such as the Three Hundred Tang Poems.

Known as an eccentric poet, Li was dubbed Ghost of Poetry (??), while Li Bai was called an Immortal of Poetry (??) and Du Fu Sage of Poetry (??). Along with Li Bai and Li Shangyin, Li He is one of the Three Lis (??) loved by Chairman Mao Zedong.

According to Sinologist Francois Jullien Li He's poetry was readmitted "at the end of the nineteenth century ... [when] ... Western notions of romanticism [ allowed] the Chinese to reexamine this poet, allowing the symbolism of his poems to speak at last, freeing his imaginary world from the never-ending quest for insinuations." (Detour and Access, p. 73)