Introduction: Development of white spot lesions on enamel is a significant and common problem during the fixed orthodontic treatment. Aim: This study was aimed to assess the effect of two types of erbium lasers (Er: YAG) laser, (Er, Cr: YSGG) laser and light cure fluoride on the enamel demineralization and surface microhardness around metal orthodontic brackets. Material and Methods: In vitro study, 90 freshlyextracted human premolars were randomly allocated to six groups (n =15) of control (neither fluoride nor laser was used), light cure fluoride varnish (Clinpro XT) on the enamel surfaces, Er: YAG laser (2.94 μm Er: YAG irradiation of the teeth), Er: YAG laser then varnishTM XT, Er Cr:YSGG laser (2.78 μm Er Cr: YSGG irradiation of the teeth), Er Cr: YSGG laser then varnish TM XT. PH cycling for 14 days through a daily  procedure of demineralization and remineralization for 6 h and 18 h, respectively. Microhardness values of enamel were evaluated with Vickers test. Two sample of each group was prepared for SEM (scanning electron microscopy) and the data from the remaining teeth were analyzed with F-test (ANOVA). Results: Microhardness mean values from high to low were as follow: varnish TM XT, Er Cr: YSGG laser then varnishTM XT, Er:YAG laser then varnish TM XT, control, Er Cr: YSGG laser, Er :YAG laser. Conclusion: Fluoride varnish alone showed the best preventive measure against enamel demineralization. There was no different between the two types of erbium laser on the effect of enamel surface microhardness.