Laser welding on dissimilar materials is widely used and has significance application in industry. Laser welding is the one of the method which can offer high strength of joint especially for joining of dissimilar metals contrast to conventional method. Conventional welding more often had an insufficient penetration depth and a wider heat affected zone which prompts to reduce joint quality. This work exhibits a weld possibility on low carbon steel and high carbon steel surface utilizing low power fiber laser in pulse wave modes. The objective of this research work is to investigate the influence of laser welding parameters of welding speed and pulse width on weld geometry of the welded metal. The parameters used is the welding speed (1.67 mm/s to 8.33mm/s) and pulse width (3 ms to 5 ms). The optimum weld geometry was with the largest aspect ratio (1.42) with parameter of welding speed (1.67 mm/s) and pulse width (3.0 ms). As conclusion, appropriate utilization of parameters can improve the quality of weld joints and durability of products.