Abstract: A far infrared (FIR)-emitting composition includes a first polymer component and a silicon dioxide composite particle which is prepared by subjecting a tetraalkoxysilane and a compound represented by Formula (A) to hydrolysis and condensation polymerization: Y—Si(ORa)3??(A), wherein each Ra independently represents a C1-4 alkyl group or a C1-4 alkanoyl group, Y represents X—R1—, a non-substituted C1-18 linear alkyl group or a non-substituted C3-18 branched alkyl group, and X and R1 are defined as set forth in the Specification and Claims. A FIR-emitting fiber including the FIR-emitting composition is also disclosed.