genus-related statistics. Previous works on the genus measurement from the WMAP simulation can be found in Park et al. (1998) and Park, Park, & Ratra (2002, hereafter PPR). This paper is organized as follows. In $\S2$, we summarise how the recent release of the WMAP 1-year CMB sky maps are reduced for data analysis. In $\S3$, we describe how the genus is measured from the CMB maps, and give results from the WMAP 1-year maps. The genus for the north and the south hemispheres of the WMAP maps are compared in $\S4$. Possible sources that can cause non-Gaussian features in the genus curve are discussed in $\S5$. We conclude in $\S6$.

WMAP 1-year Maps
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The WMAP mission was designed to make the full sky CMB maps with high accuracy, precision, and reliability. The sky map data products derived from the WMAP observations have 45 times the sensitivity and 33 times the angular resolution of the COBE/DMR mission (Bennett et al. 2003a). There are four W band ($\sim 94$ GHz), two V band ($\sim 61$ GHz), two Q band ($\sim 41$ GHz), one Ka band ($\sim 33$ GHz), and one K band ($\sim 23$ GHz) differencing assemblies, with $0\fdg21$, $0\fdg33$, 