  We investigate the electron transport and thermoelectric property of twisted
bilayer graphene nanoribbon junction (TBGNRJ) in $0^o$, $21.8^o$, $38.2^o$ and
$60^o$ rotation angles by first principles calculation with Landauer-Buttiker
and Boltzmann theories. It is found that TBGNRJs exhibit negative differential
resistance (NDR) in $21.8^o$ and $38.2^o$ rotation angles under $\pm$ 0.2 V
bias voltage. More importantly, three peak ZT values of 2.0, 2.7 and 6.1 can be
achieved in the $21.8^o$ rotation angle at 300K. The outstanding ZT values of
TBGNRJs are interpreted as the combination of the reduced thermal conductivity
and enhanced electrical conductivity at optimized angles.
