Tumor-infiltrating immune cells, as the component of tumor microenvironment, could influence tumor progress, prognosis and response to therapy profoundly. Genetic variants are considered as crucial factors that affect immune response. So far, tumor-infiltrating immune cells can be quantified from RNA sequencing data of human tumors using bioinformatics approaches based on immune-specific marker genes or expression signature. Therefore, we systematically explored the effects of single nucleotide polymorphisms (SNPs) on tumor-infiltrating immune cells, and identified immunity quantitative trait loci (immunQTLs) across 33 cancer types from TCGA.