bjective To investigate the differences between CD34 immunohistochemistry and NBT/BCIP enzymic histochemistry in displaying microvessels of various tissues. Methods The microvessels in rat small intestinal, kidney, spleen, liver, heart, lung and skin were stained by CD34 immunohistochemistry and NBT/BCIP enzymic histochemistry, and the two methods were compared by morphological analysis and microscopic count. Results We found that the microvessels in all selected tissues above mentioned were stained by CD34 immunohistochemistry, and that the microvessels in small intestinal, kidney, liver and heart tissues, but not in spleen, lung and skin tissues, were stained by NBT/BCIP enzymic histochemistry. And in the same sections of one tissue, the microvascular density by NBT/BCIP enzymic histochemistry was higher than that by CD34 immunohistochemistry. Conclusion CD34 immunohistochemistry is generally suitable to display the microvesssels in various organs, while NBT/BCIP enzymic histochemistry shows some organ microvessels at higher density.