This paper reports the pressure-temperature conditions for the vapor + liquid + liquid + hydrate four-phase equilibrium in the systems of krypton and water plus each of the following substances: cyclopentane, cyclopentene, and tetrahydropyran. The pressure ranges of the present measurements in the three systems are (0.116 to 7.664) MPa at temperatures from (283.8 to 308.5) K in the cyclopentane system, (0.121 to 2.047) MPa at temperatures from (280.2 to 297.1) K in the cyclopentene system, and (0.118 to 2.075) MPa at temperatures from (278.8 to 296.7) K in the tetrahydropyran system. These equilibrium pressures are lower by at least 4 MPa than those in the binary krypton + water system. The crystallographic structures of the hydrates are identified to be structure II based on the powder X-ray diffraction measurements.