We have first prepared non-woven, nanofibrous membranes from nano-diamond (ND) particles and multi-walled carbon nanotube-filled poly(azo-pyridine) by electro-spinning. Then, these membranes were used to obtain epoxy composites reinforced with them. Friedel-Crafts acylation and in situ polymerization were adopted to graft polyamide on multi-walled carbon nanotube (MWCNT) surface to form MWCNT-PA using -Phenyl--caprolactone. For the preparation of nanofiber, poly(azo-pyridine) (AP) was also synthesized in this work. MWCNT-PA was then electrospun with new AP and ND to yield two types of nanofibers, i.e. MWCNT/AP/PA and ND/MWCNT/AP/PA. Afterward, bisphenol A diglycidyl ether (DGEBA) matrix was reinforced with electrospun nanofiber to form two types of nanocomposites, with and with out ND. Scanning and transmission electron microscopy revealed non-woven nanofibrous membranes of MWCNT/AP/PA/DGEBA and ND/MWCNT/AP/PA/DGEBA. Compared with MWCNT/AP/PA/DGEBA 3 (3 wt.% MWCNT/AP/PA nanofibers) in DGEBA (323.6 MPa), the tensile strength for ND/MWCNT/AP/PA/DGEBA film reinforced with 3 wt.% ND/MWCNT/AP/PA nanofiber (359.4 MPa) was found to increase. Thermal stability of ND/MWCNT/AP/PA nanofiber reinforced epoxy was higher with T₁₀ 537–552°C and T_g 297–302°C relative to MWCNT/AP/PA/DGEBA system. Inclusion of ND in the system also increased the electrical conductivity of nanofiber web ND/MWCNT/AP/PA/DGEBA composites from 3.8 to 6.2 S cm^–1.