Capacity and diversity are extremely important to the quality of various phage display libraries. In this work, lambda phage-based in vitro package was applied to construct a filamentous phage display antibody library so as to enlarge its capacity and introduce more sequence diversity in the final library. In vivo recombination via Cre recombinase/lox sites was also exploited to create V-H/V-L combination diversity based on multivalent package of lambda phage packaging extracts on phagemid DNA concatemers. The library constructed with 10 mu g concatenated phagemid DNA and ten vials of lambda phage packaging extracts was calculated to contain 1.40x10(10) independent clones. Higher capacity can be easily achieved when more materials are consumed. This strategy is somewhat more efficient than prior methods.