The road traffic noise has been increasing broader effects on urban areas as well as rural areas because of rapidly increasing traffic volume and newly-constructed roads. 10 sites in building development areas were selected and the noise levels were measured by the apartment floors and by the various block plans of apartment complex. The results showed that the highest traffic noise level was obtained at the 5 and 7 floors on the apartment floors. On the basis of 7 floor with the highest level, the correction coefficient obtained from noise reduction by each floor and measurement point was -5.54 dB(A)(1st floors), -0.96 dB(A)(3rd floors), -0.38 dB(A)(5th floors), 0.00 dB(A)(7th floors), -1.98 dB(A)(l0th floors), -3.10 dB(A)(13th floors), -3.45 dB(A)(15th floors). The level of road traffic noise in the arrangement construction of right angle was about 3.0 dB(A) at N-4 point and 2.1 dB(A) at N-6 point lower than that of a plan figure, respectively. The results suggested that application of correction coefficient obtained by the apartment floor and by the arrangement construction can be improved in road traffic noise.