We investigated biomass, diatom species and fucoxanthin contents as cell growth, fatty acid and amino acid contents as nutritional composition of diatoms attached on plate to confirm effects of light emitting diodes (LEDs) due to block off natural light. In the single LED irradiation, biomass showed significantly higher to $30.0{pm}6.48mg/m^2$ in white LED than that of others (P<0.05). The dominate diatom species was Navicula cancellata. Their lipid contents showed significantly higher to $112.9{pm}19.23ug/mg$ dry matter (DM) in control than that of others LEDs. But eicosapetaenoic acid (EPA) contents showed significantly higher to $3.3{pm}0.62ug/mg$ DM than others, but not significantly differed with natural control light treatment (P<0.05). And total protein contents are higher in control and blue LED light than that of others, but essential amino acid contents showed significantly higher to $3.2{pm}4.8%$ in control (P<0.05). In mixing light with natural and LED light, biomass showed $2.6{pm}0.22mg/m^2$ in blue LED (P<0.05). Fatty acids contents were not significantly differed with all treatments. Amino acid contents showed to $11.0{pm}0.33ug/mg$ DM in white LED (P<0.05), but not significantly differed with others LED lights (P>0.05). Therefore, we could suggest that irradiation of blue LED in natural light very benefit to diatom culture for larvae of sea cucumber and abalone and do on.