Various factors affect translation effort. This research aims to explore the impact of source text type on Chinese-English translation effort with reference to translation entropy. An eye-tracking and key-logging experiment was conducted. Thirty-one student translators translated four text types, namely legal, advertising, news, and poetic texts. Data analyses show that there is a significant difference in participants’ effort of translating the four texts, which can be seen in such indicators as subjective ratings, fixation, pause, translation time, and edits. We further studied participants’ translations and calculated the translation entropy for each text type, which is a measure of uncertainty in translation. Analysis shows that there is a significant difference in translation entropy among the four text types, which provides evidence that source text features affect translation uncertainty and, hence, translation effort to search for appropriate options. The discussions are intended to provide further insight into the impact of text type on the translation process, and the result confirms the reliability of translation entropy as a predictor of translation effort.