The　works　are　focused　on　finding　out　proper　shape　of　reversed　domains　to　obtain　effective　harmonic　generations　with　high　conversion　efficiency.　The　conversion　efficiency　of　second　harmonic　wave　in　two-dimensional　nonlinear　photonic　crystals　consisting　of　square　lattice　and　reversed　domains　of　various　shapes　are　studied　numerically.　The　shapes　of　reversed　domains　are　extended　from　circle,　square　to　ellipse　and　rectangle.　The　conversion　efficiency　of　different　order　quasi-phase　matched　process　can　be　maximized　by　adjusting　the　orientation　of　noncircular　reversed　domains.　Moreover,　a　cross-shaped　reversed　domain　is　utilized　to　improve　the　conversion　efficiency　of　two-order　non-collinear　quasiphase　matching.　©　(2011)　Trans　Tech　Publications.