When developing a self-report instrument, negatively worded items were often included in a questionnaire with positively worded items to prevent response biases, such as acquiescence, affirmation, and agreement bias. Yet this strategy might interfere with examinations of the latent structure of self-report instruments and the relations with other psychological constructs. As a result, a new response bias occured, which was caused by the difference between the positively item wording and negatively item wording, so researchers named it as the method effect associated with item wording. Taking the Chinese version of Life Orientation Test-Revised (LOT-R) as an example, this study aims to explore whether the method effects associated with item wording exist in the Chinese version personality rating scales and whether they are influenced by the perfectionism and social desirability. Both CTCM (Correlated-Trait Correlated-Method) and CTCU (Correlated-Trait Correlated-Uniqueness) methods are used in model building and testing. A questionnaire including the Revised Life Orientation Test（LOT-R）, the Frost Multidimensional Perfectionism Scale (FMPS) and the Common Social desirability Scale (CSDS) is administered to 334 college students. The results show (1) that the method effects associated with item wording do exist in the Chinese version of LOT-R and they are reflected in the negatively worded items. (2) that when the method effects associated with negatively worded items are separated from the trait effects, there is only the optimism factor left in the Chinese version of LOT-R, which indicates that optimism and pessimism belong to the same personality trait instead of two different ones. (3) that the method effects associated with negatively worded items are negatively and significantly correlated with two dimensions of the perfectionism, namely the concern over mistakes and the parental expectations, but not with social desirability. Most importantly, this study finds that the method effects associated with negatively worded items can be interpreted as the Langage Labeling Effect (LLE). When you are asked, “ are you very short？” (the negatively worded item), you may feel that you are labeled as short, negative and inactive，then you may unconsciously be unpleasant. In the contrary, this Langage Labeling Effect won’t exist in the positively worded items, for example, when you are asked, “ are you very tall？” (the positively worded item), you won’t feel that you are labeled as tall, positive and active. So our understanding of the positively worded items is more realistic and neutral. The implications of this study are as follows: when developing psychological scales, the agreement bias, disagreement bias and the method effects associated with negatively worded items should be taken into account at the same time. One feasible method may be that the negatively worded items could be interpreted as filler items, but not included in the total scores. In addition, to study the essence of the personality structure, it’s necessary to separate the method effects associated with negatively worded items from the trait effects. Finally, the asymmetry of the Langage Labeling Effect is worthy of further study.