Hokkaido is a relatively high latitude area located in the northern part of Japan. Three homologous genes, Ppd-A1, PpdB1, and Ppd-D1 are mainly responsible for photoperiod response in wheat. Almost all the spring bread wheat lines bred in Hokkaido carry photoperiod sensitive allele Ppd-A1b and Ppd-B1b, but both the insensitive Ppd-D1a and sensitive PpdD1b alleles are allowed (Seki et al. 2013, Ashikaga 2015). Spring wheat cultivars released by Hokkaido, however, carry only the photoperiod sensitive allele Ppd-D1b. This implies that the Ppd-D1b allele may contribute to agronomic advantage. In Hokkaido, the effective day-length is approximately 15 hours at the spike formation stage in spring wheat. The objective of this study is to determine the effects of Ppd-D1 alleles on yield properties under long day condition in Hokkaido. Two near-isogenic lines, KH76 NILs and KH79 NILs were used in this study. The NILs were generated from crosses KH76 (PpdD1a) ×Haruyokoi (Ppd-D1b) and KH79 (Ppd-D1a) × KKH875 (Ppd-D1b) being KH76 and KH79 as recurrent parents. In each NIL, nine Ppd-D1a and nine Ppd-D1b lines were evaluated in field trials at two locations in Hokkaido (Kunneppu: [43°45′N,143°43′E], Naganuma: [43°3′N,141°45′E]) in 2018. Ppd-D1b lines headed 3-4 days later than Ppd-D1a lines in both Kunneppu and Naganuma. In KH79 NILs, Ppd-D1b lines matured significantly later than Ppd-D1a lines. Ppd-D1b lines had significantly more spikelets per spike than Ppd-D1a lines in KH76 NILs at Kunneppu and in KH79 NILs at both Kunneppu and Naganuma. The total above-ground mass was heavier in Ppd-D1b lines than Ppd-D1a lines in KH79 NILs at both locations. The grain yield of Ppd-D1b lines at Kunneppu was 107% of Ppd-D1a lines in KH76 NILs, 117% in KH79 NILs, whereas at Nagauma the grain yield was 98% in KH76 NILs and 103% in KH79 NILs. Later heading, more spikelet number per spike and heavier total above-ground mass may have contributed to the greater grain yield in Ppd-D1b lines at Kunneppu. Our results suggest that the photoperiod sensitive allele Ppd-D1b may confer a yield advantage of spring wheat in Hokkaido.