‘Yitongtianxia’ is a new tetraploid asparagus bean（ Vigna unguiculata ssp. sesquipedalis）selectively bred by genealogy method from the lines of‘ Mimeixiaoye（2X）’ with chemical mutagenesis of colchicine．The plants are trailing with strong growth vigor．Its average plant height is 306.5 cm．The internode length is 20.2 cm．It is of early maturity．The first flower sets on the 3rd node．Its growth period is about 93 days．It takes 58 days from seedling emergence to first harvest．It has strong and successive podding ability． The production ratio of double-pod and four-pod is high．The commercial pod is green white in color with shining smooth surface and beak red color．It has no rat tail and plump seed．The pod is 89.3 cm in length，about 0.9 cm in width．Its average single fruit weight is 27.4 g．There are about 20 pods per plant．It can yield about 33 t•hm-2．Its resistances to virus disease，powdery mildew and rust disease in field are stronger than that of the contrast ‘Zaojiang No.4’．And its comprehensive characteristics are super．It is suitable for cultivation in Jiangsu，Zhejiang，Anhui and Henan，etc. provinces．