This study reports the emissions of 11 trace elements (including Ti, V, Cr, Mn, Ni, Co, Cu, Zn, As, Cd, and Pb) in particulate matter with an aerodynamic diameter of <10 pm (PM10) from the combustion of 10 biofuels in a drop-tube furnace (DTF) system at 1400 degrees C in air. The 10 biofuels include four individual biofuels, i.e., biochar, bio-oil, water-soluble fraction of bio-oil (WSF), and crude glycerol (CG), and six mixed fuels, i.e., bio-oil/methanol/CG blend, WSF/CG blend, bio-oil/biochar slurry, WSF/biochar slurry, bio-oil/methanol/CG/biochar slurry, and WSF/CG/biochar slurry. The results show that the main trace elements presented in all biofuels are Zn and Mn, and the concentrations of trace elements in biochar are much higher than those in the other biofuels. In the slurry systems, the presence of Ti, V, Cr, Mn, Ni, and Co is mainly contributed by the biochar fraction, while that of the other elements (Cu, Zn, As, Cd, and Pb) is mainly from the liquid fraction. During the combustion of all of the biofuels, the elemental particle size distributions (PSDs) of both group I elements (Ti, Mn, Ni, and Co, mainly in PM1-10) and group III element (Pb, mainly in PM1) exhibit unimodal distributions. The elemental PSDs of group II elements (V, Cr, As, Cu, Zn, and Cd, predominantly in PM,) from the combustion of liquid fuels also have unimodal distributions, while that from biochar shows bimodal distributions. During the combustion of slurry fuels, the elemental PSDs of V and Cr have bimodal distributions, while those of the rest of group II (As, Cu, Zn, and Cd) exhibit unimodal distributions in PM1. On the basis of the same energy input, biochar combustion produces the highest total trace element emission in PM10 among these biofuels, followed by slurry fuels and then liquid fuels. It produces the highest emissions of Ti, Mn, Ni, V, and Cr in PM10 than the other fuels on a unit energy input basis, while combustion of liquid and slurry fuels produces the highest Pb emission, and combustion of all 10 biofuels produces similar Cu and Zn emissions. Comparisons between the experimental and calculated results of trace element emission in PM10 from mixed biofuel combustion indicate that synergies take place among individual fuel components during the combustion of the mixed biofuels, resulting in enhanced emission of trace elements in PM1.