Objective To observe stability of Traditional Chinese Medicine Injection（TCMI） when the macromolecular substances were removed. Methods Four TCMIs（Qingkailing Injection， Shuanghuanlian Injection， Danshen Injection and Dengzhanxixin Injection） approved by China Food and Drug Administration（CFDA） were introduced in the study. Protein and condensed tannin in the macromolecule-free injections were tested. The macromolecular substances were removed with molecular sieves of different pores（3k， 10k， and 30k）， and different TCMIs free of macromolecules were obtained. Ten milliliter of samples including different TCMIs free of macromolecules and the original TCMIs was added into tubes with lids and kept at 60℃ for 30 days. The visible absorption spectrum of the sample was scanned with a multi-plate reader（from 400-800nm）， and the area under the spectrum was calculated to valuate its clarity. On the 30th day， 0.5mL sample was drawn， and the macromolecular substances and precipitation were trapped on a sieve（30 k）. Results The macromolecule-free injections contained less protein and condensed tannin. The color of TCMI free of macromolecules was much lighter than that of the original one， the clarity of TCMI free of macromolecules was better than that of the original one also during the 30 days， and precipitation in the TCMI free of macromolecules trapped on the sieve was much less. Conclusion The stability of the TCMI free of macromolecules is better than that of the original one.