Complement C1q(Complement 1q) protein consists of three polypeptide chains,A,B and C,which plays an important role in stabilization of homeostasis,oxidative stress,and glucose and lipid metabolism. The aim of this study was to clone the CDS of C1QA,C1QB and C1QC genes and detect their expression patterns in various tissues,and then explore the molecular mechanism of these genes in Yak high altitude adaptation. Total RNA were extracted from various tissues,including heart,liver,spleen,lung and kidney. The mRNA expression levels of C1QA,C1QB and C1QC genes were determined by Real-time PCR. The cDNA length of C1QA,C1QB and C1QC genes were 735,744 and 732 bp,which encoded 244,247 and 243 amino acids,respectively. Bioinformatics analysis found that C1QA,C1QB and C1QC were stable hydrophilic proteins,which dominated by glycine (Gly) and proline (pro). The C1QA,C1QB and C1QC contained C1Q domain,signal peptide,and without transmembrane domain,which distributed in extracellular region. There were 18,21 and 15 phosphorylation sites in the three protein sequence,respectively. For the secondary structure of the three proteins,they were mainly composed of irregular curls,and the proportions were 61.85%,63.97% and 66.67%,respectively. Furthermore,for the expression patterns of C1QA and C1QB,lung and spleen had higher expression levels than heart,liver and kidney (P <0.01),for C1QC, heart,liver,spleen and kidney had lower expression levels than lung(P <0.01). This study may provid basic data for the functional and molecular mechanism in Yak high altitude adaptation.