Abstrak. Biochar application as an organic soil conditioner can increase plant growth and production, especially on suboptimal lands. This research aimed to determine the response of growth and production in some local sweet potato genotypes (Accession of Cengkeh Turi with yellow tuber flesh, Accession of Cengkeh Turi with orange tuber flesh, and Accession of Tanah Seribu with orange tuber flesh) on various doses application of paddy straw biochar (0, 5, 10, 15 tons/ha) in paddy fields. A field experiment was conducted from April to August 2018 in the paddy fields of Tandem Hilir I Village, Deli Serdang. The results of this research indicated that the local sweet potato genotype had a good growth and production response in paddy field cultivation. Accession of Tanah Seribu with orange tuber flesh had a significant effect on vine length, tuber weight per sample, and harvest index, while Accession of Cengkeh Turi with orange tuber flesh significantly affects the number of tubers per sample. Paddy straw biochar application had a significant effect on the length of vine, and tuber weight per sample. The best dose of paddy straw biochar in the paddy fields is 10 tons/ha.