In order to reconsider the present model of the cosmic ray in middle energy region, calculations are made for the atmospheric effects on the oblique intensity of high energy µ-mesons under the following assumptions: 1) The µ-mesons are originated only through the decay of π-mesons. 2) The source function of these π-mesons decreases exponentially with an atmospheric depth. Zenithal dependence and the absolute intensity of the µ-mesons at sea level deduced theoretically are compared with a narrow angle counter telescope experiment by Sekido, Yoshida and Kamiya. Satisfactory accordance seems to suggest the consistency of the present assumptions. Correlation coefficients of the temperature effect are also obtained on the oblique µ-mesons. It is shown that the negative temperature effect can be mainly attributed to the variation of the height of µ-meson production, but is partly dependent on the variation of the density distribution of the air. The correlation coefficients of the temperature effects on the vertical µ-meson are also compared with the experimental results of Duperier.