The zenith angle distributions of extensive air shower (EAS) at sea level were measured by the EAS arrays of Large Area Air Shower (LAAS) experiments. The distributions observed at each array were well fitted as an exponential function of (sec θ − 1). The absorption lengths λ obtained in the zenith angle distribution were about 106 ± 6 g/cm 2 for θ ≤ 45 deg. The results were also consistent with the simulation results and the results obtained by other experiments. The atmospheric effect of barometric pressure variation were also obtained in the analysis of diurnal variation of cosmic ray intensities observed at several EAS arrays. The diurnal variations of cosmic ray intensity are well described as a diurnal barometric pressure variation and higher order ones.