To figure out whether velocity components and temperature variances with the stability in the surface layer under unstable stratification satisfy the Monin-Obukhov similarity theory, the statistical characteristics of the turbulent data observed in the winter at the top of the Dangxiao Building in the urban area of Nanjing city and at three heights on the meteorological tower in the Pukou campus of Nanjing University, which lies in the suburban area, are analyzed and compared. The analysis on the data shows that the horizontal and vertical turbulent Decmalized standard deviations over the urban surface are always less than those over the suburban area. The variances with the stability in the surface layer under unstable stratification satisfy the Monin-Obukhov similarity theory. But they cannot be expressed as the empirical formula Panofsky proposed for rural underlying surface. However, the temperature turbulent Decmalized standard deviations in the urban area are larger than that over the suburban area. Meanwhile, the analysis on the suburban data at different heights shows that velocity components and temperature variances with the stability in the surface layer under unstable stratification satisfy the Monin-Obukhov similarity theory at the height of 30 m and 40 m. The temperature variances at the height of 2 m follow the same theory.