The elastic moduli are important parameters in engineering applications. In particular, the elasticity modulus and Poisson ratio are the main parameters for evaluating the bending and shear rigidity of concrete. Elastic modulus's calculations are made by taking a fixed value of concrete's Poisson ratio in the worldwide standards. The aim of this study is to show whether the Poisson ratio of concrete with different compressive strengths and different pores, saturation is a fixed value, and harmony with each other of the relationship between static and dynamic elastic moduli. Therefore, totally 540 samples were prepared. These samples consist of reinforced cubic, unreinforced cubic and unreinforced cylindrical concrete samples of the 9 concrete designs with different compressive strengths. In certain days, the ultrasonic P- and S-wave measurements and the uniaxial compressive strength test were performed on these samples exposed to water and air curing. In addition, the static and dynamic elastic moduli, the velocity ratio and the Poisson ratio of these samples were calculated using the obtained data. At the same time, the static and dynamic elastic parameters of the concrete were compared with each other depending on curing conditions because the elastic parameters could be effected from the water or air saturation of the concrete depending on location of existing structures. Consequently, new multi-parameters relationships with low RMSE were generated to determine the relationships among static and dynamic elastic parameters, and to demonstrate the effect of different curing and compressive strength conditions on static and dynamic elastic parameters. In addition, the Poisson ratio values were obtained between 0.22 and 0.34 for different curing conditions and compressive strength (2-70 MPa). This indicates that the Poisson ratio value is not a constant value.