Investigated were the sources of anxiety for learning of physical science for the eighth graders and the differences of anxiety sources with different students’ background. Twenty classes (N=635) were randomly selected from the Yi-Lan county, Taipei county and Taipei city. The questionnaire was developed by the researcher. It had been reviewed by three experts and had been modified twice based on the opinions of reviewers and pilot study. The reliability (Cronbach’s α) was .92. The findings were as follows: 1) subjects that students feared the most were mathematics (24.1%), physical science (19.7%), and English (17.1%), the main reason was that students felt the subjects were hard to understand; 2) the sources of the anxiety mainly came from “expectations”, “mathematical calculating”, “symbols of formula” and “textbooks”; 3) girls were more anxious than boys while learning of physical science (r=.13, P<.01); 4) lower physical science achievers were more anxious than higher achiever (r=.37, P<.01); 5) students whose parents received lower education were more anxious then those whose parents had higher education (r=11-.13, P<.01); 6)the school size was not correlated to students’ anxiety; 7) students in Taipei County had significantly high anxiety than other two areas (r=.16,P<.01). Recommendations were 1) further in-depth studies to understand students’ fear of mathematics and science; 2) more research of integration of science and mathematics curriculum especially in mathematic formula; 3) teachers had to make sure that students had learned the related mathematical formula and the meaning of figures and units of formula when they teach physical science.