Using scanning electronic microscope, gas hole of flowerpots were studied and analyzed quantitatively and a technical terms, gas hole degree was put forword, on which clustering analysis was based. The gas hole of inner, outer and cross sections of flowerpots had similar two-way effects on ventilation and absorption. But the direction from outer section to cross section to inner section was the main trend and the gas hole on the outer section was the main factor. According the effects of 8 types of flowerpot on the growth of chinese pink, the results indicated that Foshan earthen flowerpots were the best. As for plastic pots, the pots made in Japan were the best; Taiwan's pots ranked second; and the last one is Shunde's pots. The study also suggested that modeling through experimentation and optimal subset regression should be a good way for the development of flowerpot products.