To provide a rotary valve structure useful as an expansion valve in a cooling and heating device in which a metering amount adjusting system of plunger is eliminated and a more fine metering performance of high precision can be attained under a rotation of a rotor.

There are provided a first circumferential surface passage 25' and a second circumferential surface passage 26' extending along an outer circumferential surface 15 of a rotor 11 and an inner circumferential surface 14 of a casing 12 storming the rotor 11; the first circumferential surface passage 25' and the second circumferential surface passage 26' are arranged on a circular lotus with a rotating axis of the rotor 11 being applied as a center; an opening sectional area in an extending direction of the first and second circumferential passages 25', 26' is gradually decreased from one and end toward the other end; both ends of a through-pass hole 27 in the rotor 11 are communicated with each of the ends of the first and second circumferential surface passages 25', 26'; and further the casing 12 is provided with fluid inlet ports and/or fluid outlet ports 28, 29 communicated with each end of the through-pass hole 27 and each of the ends of the first and second circumferential surface passages 25', 26'.