This research was conducted due to the current demanding towards the production of organic agricultural product especially in vegetable crops. The aim of this research is to prove that the organic fertilizer(harvester-amino 5:5:5) which contain in organic matter may give same quality with the conventional method that using inorganic fertilizer. The objectives of this study was done to study the effect of organic fertilizer harvester-amino 5:5:5 in growth performance of Lettuce (Lactuca sativa L.) and to investigate the most preferable and suitable rate of organic matter in fertilizer that uses in fertilizing system of lettuce. This experimental study was conducted at MARDI Cameron Highland where this place was known as the low temperature land that may grow well the crops whereby Lettuce are also known as the hardy annual and suitable with the condition that are preferred. As for the control method which is using the fertigation system that are also known as the conventional method because almost 70% of Lettuce or vegetables crops nowday are using the fertigation method especially in Cameron Highland. This shows that the technology have been reach upon the time by introducing a lot of methods in agricultural industries. As for the data analysis the means, standard deviation and post hoc has been tabulated in a figure which shows the differences of the result. In addition the ANOVA two-way-test are also being used for this study as well to conclude the collected data. At the end of the study it can be conclude that the organic fertilizer are also giving a same result with the conventional method. Where the lettuce for both investigation giving almost the same rate in growth performance but still it shows that the organic fertilizer that contain in the fertilizer for organic fertilizer uses are more qualified where the freshness of Lettuce are clearly stated in the result. In addition, stated that all the findings and significant for this study were prove in a positive relationship with the objective of the study. As a conclusion, it can be conclude that all the objectives of the study were achieved.