Abstract: Under low N and P, low N and suitable fertilizer treatments, the changes of heading dates for 148 accessions of different barley genotypes were studied. The results showed as follows: (1) There was comparatively significant difference in the heading date, which of most barley under low N and P condition was later than under suitable fertilizer condition, and difference in delay days was significantly larger than barley genotype.(2) Under low N stress, the origin and row of barley would significantly influence heading date. Under suitable fertilizer, the origin of barley would significantly influence heading date．

Key words: barley, low N and P stress, heading date