With the development and implementation of new curriculum standards, the field tests of education reform in senior high schools began in 2004 in four pilot provinces in mainland China. After five years of the reform, it is necessary to know how and to what extent the curriculum standard guides test classroom instruction. The present study was conducted with the aims of quantitatively exploring the alignments between the national High School Biology Curriculum Standard and the standards-based High School Exit Exam (HSEE) of 2009 in the four provinces, using Porter's alignment model. As a result, it was found that none of the four provinces' standardised tests of 2009 analysed were significantly aligned with the national Biology Curriculum Standard. The low alignment indexes are mainly because the four HSEEs analysed generally require lower levels of cognitive skills than that of the Standard. These results deserve universal attention by both policymakers and test developers in mainland China. (Contains 12 tables and 7 figures.)