The simple P-V relation V-x(P, T) = V-x(P-0, T)/{A(x)(T)[P + P-x(T)](mx)} and T-V relation In(T/T-0) = CZ(mx), where T-0 = 1 K, T greater than or equal to 1 K, Z = {V-x(P,T)} - V(P,1)}/V-x(P,T) derived in previous works have been used to calculate the compressibility and thermal expansion coefficient for crystalline polymers based on PVT data determined by Zoller et al., Simha et al. and others. The subscript x means a state of material such as x = c for the crystalline state and x = m for the melt state, m(x) and n(x) are constants, and A(x)(T) and P-x(T) are the functions of temperature. The V-x(P-0,T) is the specific volume at constant pressure P-0 and temperature T, and V(P,1) is the specific volume at pressure P and 1 K. The average values of m(x) calculated for 20 crystalline polymers are (m) over bar(c) = 0.0892 with standard deviation sigma = 0.024 in the crystalline state and (m) over bar(m) = 0.1005 with sigma = 0.013 in the melt state. The average values of n(x) determined for the polymers are (n) over bar(c) = 0.0443 with sigma = 0.020 in the crystalline state and (n) over bar(m) = 0.1798 with sigma = 0.017 in the melt state. The P-x(T) is continuous at melting temperature T-m and changes from a quick decreasing function below T-m to a slow decreasing one above T-m for most of the crystalline polymers used in this work except for polyethylene oxide and polyoxymethylene, which show a discontinuous change at T-m and transform from a quick decreasing function below T-m to a quick decreasing one above T-m. The quantity Z is defined as the free volume fraction, and increases with increasing temperature below and above T-m. The values of Z(c) = {V-c(T-m) - V(1)}/V-c(T-m) are in the range of 0.1073 +/- 0.02, where V-c(T-m) is V at T-m in the crystalline state, and Z(m) = {V-m(T-m) - V(1))/V-m(T-m) are in the range of 0.1719 +/- 0.02, where V-m(T-m) is V at T-m in the melt state. The melting phenomena in crystalline polymers have been discussed based on the behaviour of P-x(T) and Z over the temperature range including the melting point.