Cross-over design is one of the major research methods in clinical research to evaluate the curative effect of intervening measure including random and nonrandom. Random cross-over design is different from parallel random controlled trial in measures of allocation

group setting

sample size

lost and losing follow-up. Random crossover design is used infrequently in the Chinese medicine clinical research. And in China it is used relatively a bit more than abroad. The researchers discuss implement points of random cross-over design in the Chinese medicine clinical test in order to provide the reference for the clinical researchers. The contents are including selecting intended population

variability and effects of intervening measures

difficulty in blind setting method in the control group

the outcome of cross-over test

reason analysis of lost cases

comparability of baseline and setting of washout period.