Previously, we have developed a novel method for suspension culture of anchoragedependent animal cells using biodegradable polymer nanospheres. In this study, we compared the polymer nanosphere culture method to dextran microcarrier culture method, which is a conventional suspension culture method. Most of human dermal fibroblasts (91 ± 5 %) cultured with polymer nanospheres formed aggregates on day 2. Most of cells (92 ± 7 %) attached onto microcarriers by 4 h. Microcarrier culture method had a lower apoptotic activity (3.4 folds on day 4), compared to the nanosphere culture. The microcarrier culture method had a higher cell growth (2.4-fold versus 1.7- fold growth on day 4) than the nanosphere culture. Although the polymer nanosphere culture method did not yield better outcomes than the microcarrier culture, the polymer nanosphere culture method may offer advantages over the microcarrier culture method with respect to cell protection from the shear stress during agitation at high speed and cell transplantation without enzyme digestion process to harvest cultured cells.