- 天然气 tiānránqì natural gascombustible gas found in underground rock formations or coal beds, used as fuel or raw material in chemical production
- 天然林 tiānránlín natural forestA forest that has grown naturally through self-seeding or other biological processes, rather than being planted by humans.
- 中国石油天然气集团公司 zhōngguóshíyóutiānránqìjítuángōngsī China National Petroleum CorporationChina National Petroleum Corporation (CNPC)
- 天然资源 tiānránzīyuán natural resourcesnatural resources found in nature, such as minerals, forests, or water power sources, and water
- 天然瓦斯 tiānránwǎsī natural gasNatural gas, mainly composed of methane, produced naturally underground (Taiwan usage, called [[天然气|天然氣|tian1 ran2 qi4]] in Mainland China)
- 天然气水合物 tiānránqìshuǐhéwù natural gas hydratea crystalline solid resembling ice that consists of natural gas molecules, typically methane, trapped within a lattice of water molecules
- 天然气汽车 tiānránqìqìchē natural gas vehiclea motor vehicle that uses compressed natural gas or liquefied petroleum gas as its fuel
- 天然淘汰 tiānrántáotài natural selectionSurvival of the fittest; the process in nature by which only the organisms best adapted to their environment tend to survive and transmit their genetic characters
- 天然煤气 tiānránméiqì natural gasCombustible gas found naturally underground; same as [[天然气|天然氣|tian1 ran2 qi4]]
- 天然痘 tiānrándòu smallpoxan acute infectious disease caused by the variola virus, characterized by high fever and skin eruptions, and preventable by the [[牛痘|牛痘|niu2 dou4]] vaccine
- 天然纤维 tiānránxiānwéi natural fiberA general term for any fiber derived from nature, including animal fibers like wool or silk, plant fibers like linen or cotton, and mineral fibers.
- 天然能源 tiānránnéngyuán natural energy sourceEnergy sources found in nature that have not been processed or converted, such as coal, oil, natural gas, or water power; also known as [[一次能源|一次能源|yi1 ci4 neng2 yuan2]] or [[初级能源|初級能源|chu1 ji2 neng2 yuan2]].
- 天然铀 tiānrányóu natural uraniumUranium that is extracted from ore and has not undergone isotope separation; it consists mostly of uranium-238 with a small amount of uranium-235
- 液化天然气 yèhuàtiānránqì liquefied natural gasliquefied natural gas, consisting primarily of methane and used as a household fuel; often referred to by the abbreviation LNG
- 纯真天然 chúnzhēntiānrán natural and authenticpure and natural; authentic and sincere in character or quality
- 含油天然气 hányóutiānránqì petroleum gasnatural gas containing oil or liquid hydrocarbons; petroleum gas
- 天然免疫 tiānránmiǎnyì natural immunityProtective immunity that is either innate or naturally acquired through exposure to a disease; also known as [[自然免疫|自然免疫|zi4 ran2 mian3 yi4]].
- 天然呆 tiānrándāi space cadet(loanword from Japanese 'tennen boke') a character archetype describing someone who is naturally muddleheaded, slow to react, and innocently ditzy. It refers to a person who makes silly mistakes or acts in a foolish way without realizing it, often creating a humorous or cute effect.
- 天然橡胶 tiānránxiàngjiāo natural rubberA highly elastic polymer made from the sap of rubber trees, used to manufacture tires and other rubber products
- 天然毒素 tiānrándúsù natural toxinA toxic substance produced naturally by a living organism, such as a plant, animal, or fungus
