This study investigated the biology cognitive preferences of pre- and in-service biology teachers and examined the relationships between cognitive preferences and teacher attributes related to teaching competency. The results showed that the subjects exhibited a cognitive preference style of Questioning (Q), Principles (P) ＞ Application (A) ＞ Recall (R). This indicated that the subjects displayed a strong preference for questioning and principles and a weak preference for memorizing biological information. Significant differences in the biology cognitive preference styles were found among three groups of subjects, namely, preservice (Seniors), biology-major (BM) and nonbiology-major (NBM) biology teachers. Seniors exhibited a cognitive preference style of Q＞P, A＞R which indicated a strong preference for questioning and a weak preference for recall. BM exhibited a cognitive preference style of Q, P, A＞R which indicated a strong preference for questioning, principles and application and a weak preference for recall. While NBM exhibited a cognitive preference style of P＞A, R, Q which indicated a strong preference for principles and a weak preference for application, recall, and questioning. In addition, Seniors and BM showed a higher preference for Q mode and a lower preference for R and P modes than NBM. Biology subject-matter competency and scientific attitudes correlated positively with Q preference mode, but negatively with R preference mode. However, no significant correlation was found between biology subject matter competency, scientific attitudes and P and A preference modes. Biology inquiry skills and the understanding of the nature of science of preservice teachers correlated positively with P preference mode. But, no significant correlation was found between the two teacher attributes and the other three cognitive preference modes. The subjects were further categorized into three groups based on Q-R scores, namely as Q-type (critical questioning), M-type (Medium), and R-type (memorizing information). Oneway ANOVA revealed that the biology subject matter competency and scientific attitudes of Q-type teachers were significant better than those of M- and R-type teacher groups. While no significant differences were found between M- and R-type teacher groups.