Two-dimensional faceted dendrite growth of silicon from undercooled melt of Si-6 wt%Ni alloy was experimentally investigated, in which molten alloy film from 10 to 20 mm in thickness was undercooled up to 115 K and growing dendrites were observed in situ. Both the in situ observation of dendrite morphology and the EBSP crystallographic analysis for solidified samples showed that both a /2 1 1S twin dendrite and a /1 0 0S twin-free dendrite grew in the range of undercooling from 50 to 115 K. Dendrite growth velocity was also measured for different undercooling conditions. The growth velocity of /2 1 1S dendrites was slightly larger than that of /1 0 0S dendrites. It is concluded that the upper envelope of the data provide the correct dendrite growth velocity and it is compared with that obtained by phase-field simulations. Growth velocity in both follows power relationships to undercooling and the linear kinetic coefficient is estimated to be 0.01 m/s K. r