Innovative solutions?in clean technology enterprises?have?the characteristics of?cross-discipline and multilevel. For those kinds of enterprises, patent portfolio is a necessary and powerful tool to protect their innovations and obtain the sustainable competitiveness. A case study on the construction process?of patent portfolio?of a typical wind energy enterprise shows that building an effective patent portfolio must be based on good understanding of both development trend and competition state of technology. Also, a general?pattern of patent portfolio strategy in clean technology enterprises is?revealed by the case.?While, through the analysis of the patent literature on carbon capture and sequestration field, it is found that patent portfolio analysis can be applied to monitor the technology and competitive state of the field concerned by providing multi-layered visual information and intelligence for the the construction of patent portfolio in clean technology enterprises.