We have observed electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) in room temperature rubidium vapor, by coherent population trapping on the Zeeman substates formed by a magnetic field co-linear with a laser beam passing through the vapor. We have observed with good signal-to-noise ratio EIT on the F = 2 →F¿¿¿¿ transitions in 85Rb and on the F = 1 → F¿¿¿¿ transitions in 87Rb. EIA has been observed on the F = 3 → F¿¿¿¿ transitions in 85Rb and on the F = 2 → F¿¿¿¿ transitions in 87Rb.