The natural phenophases of plants and animals are changing because of the global warming. In order to reflect accurately the ecological environment change by the phenological observation records so to provide reliable basic data for scientific research in climate, agricultural and animal husbandry, an analysis is made of all kinds of fault circumstances frequently occurred in the observation records by using the phenological observation records of woody plants, herb, animal and meteorological and hydrological phenomena of Qinghai Province from 1994 to 2003. The reasons for fault records are discussed and the solutions for decreasing and clearing off the fault records in natural phenological observation records are proposed, aiming to improve the accuracy of phenological observation records.