Spike compactness (SC) and length (SL) are the components of spike morphology and are strongly related to grain yield in wheat ( L.). To investigate quantitative trait loci (QTL) associated with SC and SL, a recombinant inbred lines (RIL) population derived from the cross of Bailangmai (BLM, a Tibet landrace) and Chuanyu 20 (CY20, an improved variety) was employed in six environments.