Abstract: By the bioassay of Agar-Soil-Sandwich Method (ASSM) and field investigation, 90 wheat cultivars (originating from China and abroad) were used to evaluate the allelopathic potential and screene several stronger allelopathic wheat germplasm. 5 wheat cultivars “115/Qinghaimai”, “92L89”, “Baiquan3199”, “81-214” and “92H31”, tested for strong allelopathic potential, were screened by ASSM method. The results show that different wheat cultivars have significantly different allelopathic potential, with inhibition rate (IR) of 10.1%～69.1% against lettuce (Lactuca sativa L.). Lettuce root IR in the 5 selected wheat cultivars is 69.1%, 68.5%, 68.7%, 69.1% and 65.2% respectively. In addition, 2 weak allelopathic potential wheat cultivars, “Kang 10103(80)” and “A246”, with IR of 10.1% and 12.2%, are found among the tested germplasms. The wheat germplasm, following the stronger allelopathic potential test by ASSM bioassay also shows strong allelopathic potential in the field, and confirmed by relay seeding in the agar method. This suggests that ASSM is a feasible method for screening allelopathic wheat. Consequently, the screened wheat cultivars are valuable for allelopathic wheat breeding, which can serve as an important germplasm. This can equally be a reference method in screening allelopathic potential in wheat germplasm.