The field observation over a densely built-up residential area in Tokyo, Japan, is performed using a tower. The plan area index of the buildings in the observation site is 0.48. The nature of the turbulent transfer of momentum, heat, vapor, and CO₂ is investigated using the correlation coefficients and wavelet analysis. In this study, turbulence data, i.e. the fluctuations of three dimensional wind velocity, temperature, vapor density, and CO₂ concentration, sampled with 8 Hz and measured at the height z/h=4.0 (with z=29 m as the sensor height and h=7.3 m as the average height of buildings) for 8 months are analyzed. Following conclusions are obtained.

(1) The ratio of transfer efficiency of heat and momentum, r_wT/r_uw , as a function of the atmospheric stability, z'/L , agrees well with existing function form provided in other cities.

(2) The transfer efficiency ratio of vapor for momentum, r_wq/r_uw , is smaller than provided function form. The ratio of CO₂ for momentum, r_wc/r_uw , is much smaller, and its dependence on the atmospheric stability is not found.

(3) Wavelet analysis shows the contribution of various scale of turbulence to the each scalar tranport (heat, vapor, and CO₂). In the morning, the thermally convective large-scale motions are dominant. In such an unstable condition, water vapor is transferred effectively. On the other hand, in the dattime, the heat and vapor are similarly transferred by small-scale turbulence (organized structure and wake), but, in thermal-scale, vapor and CO₂ are not or adversely transferred while heat is effectively transferred.