Abstract: Counseling process-outcome research studies process variables’ impact on outcome. Person-centered theory, cognitive theory, behavior theory, psychoanalytic theory and some other theories all contributed to this research field. Process-outcome research focuses on the relationships between process variables and outcome. Main process variables under research are therapist response modes, client behavior in counseling, therapeutic alliance and important contents in counseling. Fruits in this field are not so rich at present, probably because the relationship itself is very complicated. Besides, there are some limitations with research methods, such as some designs are too simple for complicated relationships, too many measure tools lead to hardness of results comparison, some measure tools are not mature, reliability and validity are poor. In addition to conquering these problems, future research should consider more on theory construction, inner variables’ moderator and mediator effects, and client variables. Besides, research methods should be more integrative and diversified

Key words: counseling, process-outcome research, process variable, outcome variable