Stacked In0.15Ga0.85As quantum wire (QWR) laser structures were grown on (775)B-oriented GaAs substrates by molecular beam epitaxy. The laser active region consists of three 2.4-nm-thick QWR layers separated by thin (0.5 or 1 nm thick) AlAs barriers. It showed better one-dimensionality than that of nonstacked (775)B QWRs. The stacking (775)B QWR lasers oscillated at room temperature with the threshold current density of about 3 kA/cm(2) under the pulsed current condition. They showed the characteristic temperature of T-0 similar to243 K in the temperature range of 20-80 degreesC, which is very high not only T-0 values of previous (775)B QWR lasers but also among those of the low-dimensional quantum structure lasers reported so far.