The curve curvature variation plot is a common method for analyzing curve quality. An intuitive and efficient planar B-spline curves fairing method with curvature variation was brought forward. The trend of curvature monotone variety and the location of curvature extremum points and inflection points and flat points were designed by using target curvature plot. Minimization of discrete points' energy of curve segments and the difference between faired curve and original curve was regarded as objective function of curve fairing optimization algorithm, and the information (the trend of curvature monotone variety for every curve segment) provided by target curvature plot reflecting design intent has been treated as constraint condition of curve fairing optimization algorithm. This algorithm made faired curve curvature monotone and equable variation. Finally，an example verified the validity of this algorithm.