The purpose of the study is to compare the effect of scientific attitudes toward the science process skills In Physics Practicum by using Peer Model (1) and conventional model (2). PEER is an acronym of planning, experiment, evaluate, and reporting, which is the stage of the model's practicum. The scientific attitudes (x) here are: honesty, collaboration, discipline, responsibility, open-mindedness. Scientific process skills (y) are defined as: classifying, making question, identifying and controlling variables, measuring, and inferring. The type of research is experimental with the static-group comparison design. The subjects of this research are 44 Physics Department students of Universitas Negeri Surabaya. The scores of scientific attitudes and science process skills come from the score of performance tests by using performance assesment instruments. The data analysis uses Correlation and t test. The results show that: 1) the relationship between scientific attitudes and science process skills for 5 practicum topics is considered moderate (r₁ = 0.57967 and r₂ = 0.39361); 2) The scores of scientific attitudes and scientific process skills between PEER model and conventional model are significantly different (t_x = 3.77777 and t_y = 5,28380, with t₀ = 2,13185 and α = 0,05); 3) The average score of PEER model scientific attitudes (x₁ = 4,8 ± 0,1) is better than conventional model (x₂ = 4,1 ± 0,4) while the average score of PEER model science process skills (y₁ = 4,1 ± 0.3) is better than the conventional model (y₂ = 3.2 ± 0.5). The results of this study conclude that the scientific attitudes have positive effects on the improvement of science process skills in Physics practicum by using PEER model.