The tracks cross-section morphological variaiton of single laser with the controllable processing parameters, such as laser power, scanning speed, and powder mass flow rate, is observed by means of the single laser cladding experiment. A curvilinear equation describing cross-section morphology controlled by a single parameter (δ=wtan β/2h) is proposed. According to the measurement datas of cross-section geometrical characteristic parameters: width w, height h, area F and deposition angle β, the functional relationship between the parameter δ and the nominal area Fm (Fm=wh) of the cross-section is established by applying the regression processing method. And the regularity of cross-section morphology is determined with the variation of Fm. The curvilinear equation of cross-section morphology is testified by the measurement datas of F and β.