Views on the nature of human essay rating process have evolved from the behaviorism to the cognitive and to the recent social cognitive view. The recent view witnesses a number of studies on the interference of test institutional constraints on essay raters’ behavior. There are, however, few studies investigating raters’ social psychological considerations when rating an essay. The purpose of the present study was to explore the TEM8 (tests for English majors) raters’ social psychological considerations in the essay rating process through analyzing raters’ think aloud protocols while doing rating and their reports on the follow up interviews. All the think aloud reports and interview reports were analyzed using Nvivo. Data analysis revealed six types of social psychological considerations raters will take in the rating process: Institutional awareness, knowledge of rating system, Physical condition, Test knowledge, Test taker expectation, Ethical consideration. Although those considerations are irrelevant to text quality, they play a role in the scoring of a text, making the actual score not the real reflection of text quality. Those elements are related either to test institution or to raters’ personal features. Based on the findings, several suggestions on rater training were made: 1) Improving the standard in choosing raters; 2) establishing raters’ rating files to recruit those with good recordings and exclude the unqualified raters; 3) including mechanism of the test institution, rating supervision methods into rater training content; 4) unifying raters’ understanding on test purpose, test nature and test impact; 6) improving raters’ professional morality and test fairness awareness.